CLEP Precalculus · Mock Exam 1
CLEP Precalculus

CLEP Precalculus — Mock Exam


Exam Overview

This mock exam mirrors the College Board CLEP Precalculus exam: 48 questions, 90 minutes, computer-delivered. On the real exam the questions are split into two sections with a calculator quirk:

Some real items are numeric-entry (you type the answer). For clean self-grading, all 48 questions here are presented as five-choice multiple choice (A–E), exactly one correct. Practice Section 2 discipline by working the no-calculator topics (identities, exact values, factoring, exponent rules) entirely by hand.

Scoring: scores are reported on a 20–80 scaled score. The American Council on Education (ACE) recommends granting credit at a scaled score of 50, which corresponds to roughly half the questions correct. Use the estimator at the bottom to convert your raw score.

Blueprint

Official content area Weight Questions
Algebraic Expressions, Equations, and Inequalities 20% 10
Functions: Concept, Properties, and Operations 15% 7
Representations of Functions (Symbolic, Graphical, Tabular) 30% 14
Analytic Geometry 10% 5
Trigonometry and its Applications 15% 7
Functions as Models 10% 5
Total 100% 48

Bloom target: Apply + Analyze + Evaluate ≥ 60% of items (this exam runs ~88%). Answer-distribution target: each letter 15–25% of the key. Topics are interleaved so the sequence feels like a real mixed CLEP form.

Questions

Question 1
For x > 0, the expression (8x⁶)^(2/3) is equivalent to
Question 2
If f(x) = 2x² − 3x + 1, then f(a + 1) =
Question 3
A function is given by the table below.

x 0 1 2 3
f(x) 3 6 12 24

Which of the following defines f?

Question 4
The exact value of cos(5π/6) is
Question 5
The equation x² + y² − 6x + 4y − 12 = 0 is a circle with
Question 6
The graph of y = f(x) is shifted 3 units to the right and 2 units down to produce the graph of g. Then g(x) =
Question 7
A colony of bacteria doubles every 4 hours and starts with 500 cells. Which function gives the population after t hours?
Question 8
The solutions of 2x² − 5x − 3 = 0 are
Question 9
[GRAPH: A downward-opening parabola in the xy-plane with vertex (−1, 4), passing through (0, 3) and (1, 0).] Which of the following could be its equation?
Question 10
If f(x) = 3x − 2 and g(x) = x², then (f ∘ g)(−2) =
Question 11
In a right triangle, an acute angle θ satisfies sin θ = 5/13. Then cos θ =
Question 12
The domain of f(x) = √(2x − 6) / (x − 5) is
Question 13
The solution set of |2x − 1| < 5 is
Question 14
The distance between the points (−2, 3) and (4, −5) is
Question 15
[GRAPH: An exponential decay curve in the xy-plane through (0, 4), (1, 2), and (2, 1), with horizontal asymptote y = 0.] Which of the following could be its equation?
Question 16
A phone plan charges a $25 base fee plus $0.15 per minute. What is the cost of a month with 100 minutes of calls?
Question 17
Which of the following functions is odd?
Question 18
Let f(x) = x + 4 for x < 0, f(x) = x² for 0 ≤ x < 3, and f(x) = 2x for x ≥ 3. Then f(−3) + f(2) + f(3) =
Question 19
The solution set of √(x + 6) = x is
Question 20
On the interval [0, 2π), the solutions of 2 sin x − 1 = 0 are
Question 21
If log₂ x = 5, then x =
Question 22
The line perpendicular to y = (2/3)x + 1 and passing through (4, −1) has equation
Question 23
If f(x) = (x − 1)/(x + 2), then f⁻¹(x) =
Question 24
The graph of y = f(x) is reflected across the x-axis and then shifted up 3 units. The result is the graph of
Question 25
The solution (x, y) of the system 2x + y = 7 and x − y = 2 is
Question 26
A ball's height in feet after t seconds is h(t) = −16t² + 32t + 48. The maximum height reached is
Question 27
A function is given by the table below.

x 1 3 6
f(x) 4 10 25

The average rate of change of f from x = 1 to x = 6 is

Question 28
For sin θ ≠ 0, the expression (1 − cos²θ)/sin θ simplifies to
Question 29
The number of real solutions of x² − 4x + 7 = 0 is
Question 30
A polynomial function of degree 3 has a positive leading coefficient, a zero of multiplicity 2 at x = −2, and a zero of multiplicity 1 at x = 3. Which statement describes its graph in the xy-plane?
Question 31
If f(x) = √x and g(x) = x − 4, the domain of (f ∘ g)(x) is
Question 32
The graph of x²/9 + y²/25 = 1 is an ellipse whose major axis is
Question 33
The graph of y = f(2x) is obtained from the graph of y = f(x) by a
Question 34
The solution of 1/x + 1/3 = 1/2 is
Question 35
The period of the function y = 3 sin(2x − π) is
Question 36
The product (3 + 2i)(1 − 4i) equals
Question 37
A 80-gram radioactive sample has a half-life of 6 years. How many grams remain after 18 years?
Question 38
For f(x) = x², the difference quotient [f(x + h) − f(x)]/h, with h ≠ 0, simplifies to
Question 39
[GRAPH: A sine curve in the xy-plane with midline y = −1, amplitude 3 (maximum 2, minimum −4), and period 2π, passing through (0, −1) while rising to its maximum at x = π/2.] Which of the following could be its equation?
Question 40
The solution set of x² − x − 6 > 0 is
Question 41
From a point on level ground 40 feet from the base of a tree, the angle of elevation to the top of the tree is 30°. The height of the tree is
Question 42
[GRAPH: The graph of y = f(x) in the xy-plane has a local maximum at (−1, 4) and a local minimum at (2, −3), rising to the left of x = −1, falling between them, and rising again to the right of x = 2.] On which interval is f decreasing?
Question 43
A circle has center (−1, 4) and passes through the point (2, 0). Its equation is
Question 44
The vertical asymptote of the graph of f(x) = log(x − 3) is
Question 45
The solutions of |3x − 2| = 7 are
Question 46
A car worth $20,000 depreciates by 15% of its value each year. Its value after 2 years is
Question 47
Which of the following functions is one-to-one, and therefore has an inverse that is also a function?
Question 48
The exact value of tan(π/4) + sin(π/6) is
Show answer key & explanations

Answer Key

1. A) 4x⁴. Distribute the outer exponent to every factor: 8^(2/3) = (∛8)² = 2² = 4, and (x⁶)^(2/3) = x^(6·2/3) = x⁴, giving 4x⁴. Distractors: B) 8x⁴ leaves the 8 untouched, but the exponent applies to it too. C) 16x⁴ computes 8·2 = 16 instead of (∛8)². D) 4x⁹ inverts the exponent on x, dividing 6 by 2/3 instead of multiplying. E) 6x⁴ mis-evaluates 8^(2/3) as 6. Fix: on a power, take the root (denominator) first, then the power (numerator), and apply the outer exponent to each inside factor. [Apply]

2. C) 2a² + a. Substitute: 2(a+1)² − 3(a+1) + 1 = 2(a²+2a+1) − 3a − 3 + 1 = 2a² + 4a + 2 − 3a − 2 = 2a² + a. Distractors: A) 2a² − 3a + 2 computes f(a) + 1, treating f(a+1) as f(a) + 1. B) 2a² + 4a + 2 expands only the squared term and drops −3(a+1) + 1. D) 2a² − 3a uses (a+1)² = a² + 1, losing the middle term 2a. E) 2a² + 7a + 6 flips the sign of the −3(a+1) term to +3(a+1). Fix: replace every x with the whole input (a+1), then expand (a+1)² = a² + 2a + 1 in full. [Apply]

3. E) f(x) = 3·2^x. Outputs multiply by 2 at each step (3→6→12→24), a constant ratio, so the function is exponential with initial value 3 and base 2: f(x) = 3·2^x, which reproduces 3, 6, 12, 24. Distractors: A) 3x + 3 is linear, matching only the first gap (gives 3, 6, 9, 12). B) 2·3^x swaps the initial value and the growth factor (gives 2, 6, 18, 54). C) 3x² + 3 forces a quadratic (gives 3, 6, 15, 30). D) 3 + 2^x gives 4, 5, 7, 11 and fails even at x = 0. Fix: constant differences signal linear; constant ratios signal exponential y = (initial)·(ratio)^x. [Analyze]

4. B) −√3/2. The angle 5π/6 = 150° lies in Quadrant II with reference angle π/6; cosine is negative there, so cos(5π/6) = −cos(π/6) = −√3/2. Distractors: A) √3/2 drops the negative sign required in Quadrant II. C) −1/2 is cos(2π/3), not cos(5π/6). D) 1/2 confuses it with sin(5π/6). E) −√2/2 belongs to 135° (3π/4), a different reference angle. Fix: find the reference angle, take the exact value there, then attach the sign from the quadrant. [Remember]

5. D) center (3, −2), radius 5. Complete the square: (x² − 6x) + (y² + 4y) = 12 → (x − 3)² − 9 + (y + 2)² − 4 = 12 → (x − 3)² + (y + 2)² = 25, so center (3, −2), radius √25 = 5. Distractors: A) (−3, 2), r = 5 flips both center signs. B) (3, −2), r = 25 reports r² as the radius. C) combines both errors. E) (6, −4), √12 reads coefficients directly without completing the square. Fix: center coordinates are the opposite of the numbers inside the squared terms, and the radius is the square root of the right-hand side. [Apply]

6. A) f(x − 3) − 2. A shift right by 3 replaces x with (x − 3) inside the function; a shift down by 2 subtracts 2 outside: g(x) = f(x − 3) − 2. Distractors: B) f(x + 3) − 2 shifts left (inside sign reversed). C) f(x − 3) + 2 shifts up instead of down. D) f(x − 2) − 3 swaps the horizontal and vertical amounts. E) f(x + 3) + 2 reverses both directions. Fix: inside changes act horizontally and opposite to the sign; outside changes act vertically and with the sign. [Understand]

7. C) P(t) = 500·2^(t/4). Doubling means base 2; "every 4 hours" makes the exponent t/4 (the number of 4-hour periods), so P(t) = 500·2^(t/4). Check t = 4: 500·2¹ = 1000, one doubling. Distractors: A) 500·2^(4t) doubles every 1/4 hour. B) 500·2^t doubles every hour. D) 500·4^t quadruples every hour. E) 500 + 2^(t/4) adds instead of scaling, breaking the initial value. Fix: exponent = (elapsed time) ÷ (time per one doubling); the growth factor multiplies, never adds. [Apply]

8. B) x = −1/2 and x = 3. Factor: 2x² − 5x − 3 = (2x + 1)(x − 3) = 0, so x = −1/2 or x = 3. Distractors: A) x = 1/2, −3 flips both signs. C) x = −1/2, −3 gets the sign of the 3-root wrong. D) x = 1/2, 3 mishandles the 2x + 1 factor. E) x = 2, −3 factors the constant without the leading 2. Fix: set each factor to zero; from (2x + 1) the root is −1/2, not −2. [Apply]

9. D) y = −(x + 1)² + 4. Vertex (−1, 4) gives y = a(x + 1)² + 4; using (0, 3): a(1) + 4 = 3, so a = −1. Then y = −(x + 1)² + 4, and (1, 0) checks: −(2²) + 4 = 0. Distractors: A) opens upward (a = +1), contradicting the downward shape. B) y = −(x − 1)² + 4 puts the vertex at x = +1. C) has vertex (−1, −4), below the x-axis. E) y = −(x + 1)² + 3 lowers the vertex to 3 and fails (0, 3). Fix: read the vertex into a(x − h)² + k (inside sign reversed), then solve for a with a second point. [Analyze]

10. E) 10. Work inside out: g(−2) = (−2)² = 4, then f(4) = 3(4) − 2 = 10. Distractors: A) 64 reverses the order, computing g(f(−2)) = g(−8). B) −14 uses g(−2) = −4 (sign error squaring). C) 16 stops at g of an intermediate value. D) −8 reports only f(−2). Fix: (f ∘ g)(x) means f(g(x)) — evaluate the inner function g first. [Apply]

11. A) 12/13. For an acute angle, cos²θ = 1 − sin²θ = 1 − 25/169 = 144/169, so cos θ = 12/13 (positive in Quadrant I). This is the 5–12–13 right triangle. Distractors: B) 13/12 is sec θ, the reciprocal. C) 5/12 is tan θ. D) 12/5 is cot θ. E) 8/13 uses a wrong leg length (8 is not the missing side). Fix: with sin = opp/hyp = 5/13, the adjacent leg is √(13² − 5²) = 12, so cos = 12/13. [Apply]

12. C) x ≥ 3, x ≠ 5. The radicand needs 2x − 6 ≥ 0, i.e. x ≥ 3, and the denominator forbids x = 5; combine to x ≥ 3 with x ≠ 5. Distractors: A) x ≥ 3 ignores the denominator restriction. B) x > 3 wrongly excludes the endpoint 3, where the numerator is 0 but the function is defined. D) drops the square-root requirement entirely. E) 3 ≤ x ≤ 5 invents an upper bound. Fix: intersect two conditions — radicand ≥ 0 (endpoint included) AND denominator ≠ 0. [Analyze]

13. B) −2 < x < 3. |2x − 1| < 5 means −5 < 2x − 1 < 5; add 1: −4 < 2x < 6; divide by 2: −2 < x < 3. Distractors: A) x < 3 keeps only one side. C) x > −2 keeps only the other side. D) x < −2 or x > 3 is the solution to the greater-than inequality |2x − 1| > 5. E) −3 < x < 2 mishandles the arithmetic after isolating x. Fix: |A| < c becomes the compound −c < A < c (an "and"); |A| > c becomes an "or." [Apply]

14. D) 10. Distance = √((4 − (−2))² + (−5 − 3)²) = √(6² + (−8)²) = √(36 + 64) = √100 = 10. Distractors: A) √14 adds the coordinate differences (6 + 8 = 14) before rooting. B) 14 adds |6| + |8| with no rooting. C) √28 mishandles the squares. E) √52 squares only part of the differences (e.g., 6² + 4²). Fix: distance = √((Δx)² + (Δy)²); square the differences, add, then take one square root. [Apply]

15. E) f(x) = 4·(1/2)^x. The curve decays with initial value 4 and halves each step (4→2→1), so base 1/2: f(x) = 4·(1/2)^x, matching all three points. Distractors: A) 4·2^x grows instead of decaying. B) 4 + (1/2)^x has y-intercept 5 and asymptote y = 4, not y = 0. C) 4/x is undefined at x = 0. D) 2·(1/2)^x has y-intercept 2, not 4. Fix: decay → base between 0 and 1; the y-intercept fixes the initial value, the ratio fixes the base. [Analyze]

16. A) $40. Cost = 25 + 0.15(100) = 25 + 15 = $40. Distractors: B) $15 drops the base fee. C) $125 ignores the per-minute rate and adds the minutes as dollars (25 + 100). D) $375 multiplies base × rate × minutes. E) $2,500 multiplies base × minutes, ignoring the rate. Fix: a linear model is (fixed base) + (rate × quantity); add the flat fee once, scale only the variable part. [Apply]

17. B) f(x) = x³ − x. A function is odd when f(−x) = −f(x). Here f(−x) = (−x)³ − (−x) = −x³ + x = −(x³ − x) = −f(x), so it is odd. Distractors: A) x² + 1 is even, f(−x) = f(x). C) |x| is even. D) x³ + 1 gives f(−x) = −x³ + 1, neither odd nor even. E) x² − x mixes an even and an odd term, so it is neither. Fix: odd means every term has an odd power and no constant; test f(−x) = −f(x). [Analyze]

18. C) 11. Match each input to its condition: −3 < 0 → f(−3) = −3 + 4 = 1; 0 ≤ 2 < 3 → f(2) = 2² = 4; 3 ≥ 3 → f(3) = 2(3) = 6. Sum = 1 + 4 + 6 = 11. Distractors: A) 9 uses the wrong branch for one input. B) 13 squares −3 by using the middle branch. D) 17 uses 2x for f(2) as well. E) 7 evaluates only f(3). Fix: for each input, first decide which condition it satisfies, then use only that branch. [Apply]

19. D) x = 3. Square both sides: x + 6 = x², so x² − x − 6 = 0 = (x − 3)(x + 2), giving x = 3 or x = −2. Check in the original: √9 = 3 ✓, but √4 = 2 ≠ −2, so x = −2 is extraneous. Only x = 3 works. Distractors: A) keeps both roots without checking. B) keeps the extraneous root and discards the valid one. C) declares both valid. E) claims no solution, but x = 3 checks. Fix: squaring can create extraneous roots — always substitute back into the original radical equation. [Evaluate]

20. E) x = π/6 and x = 5π/6. Solve sin x = 1/2 on [0, 2π): the reference angle is π/6, and sine is positive in Quadrants I and II, giving x = π/6 and x = π − π/6 = 5π/6. Distractors: A) π/6 only omits the second-quadrant solution. B) π/3, 2π/3 solves sin x = √3/2. C) π/6, 7π/6 uses Quadrant III (where sine is negative). D) π/6, 11π/6 uses Quadrant IV. Fix: after the reference angle, place solutions in the quadrants where the function has the required sign — sine positive means Q I and Q II. [Apply]

21. A) 32. log₂ x = 5 means x = 2⁵ = 32. Distractors: B) 25 computes 5². C) 10 computes 5·2. D) 7 computes 5 + 2. E) 64 computes 2⁶. Fix: log_b x = y converts to x = b^y — the base raised to the log. [Apply]

22. B) y = −(3/2)x + 5. The perpendicular slope is the negative reciprocal of 2/3, which is −3/2. Point-slope through (4, −1): y + 1 = −(3/2)(x − 4) = −(3/2)x + 6, so y = −(3/2)x + 5. Distractors: A) reuses the original slope 2/3. C) y = −(3/2)x − 7 uses the right slope but a sign error placing the point. D) y = (3/2)x − 7 forgets the negative in the reciprocal. E) uses the negative of the original slope (−2/3) rather than its reciprocal. Fix: perpendicular slope = negative reciprocal (flip and change sign), then anchor with the given point. [Apply]

23. C) (2x + 1)/(1 − x). Set y = (x − 1)/(x + 2) and solve for x: y(x + 2) = x − 1 → yx + 2y = x − 1 → x(y − 1) = −1 − 2y → x = (2y + 1)/(1 − y). Swapping variable names, f⁻¹(x) = (2x + 1)/(1 − x). Check x = 0: f(0) = −1/2 and f⁻¹(−1/2) = 0 ✓. Distractors: A) (x + 2)/(x − 1) merely flips the fraction. B) (2x + 1)/(x − 1) has the wrong denominator sign. D) (1 − x)/(2x + 1) inverts the correct answer. E) is the original function unchanged. Fix: swap x and y, then solve for y — collect all y-terms on one side and factor. [Apply]

24. D) y = −f(x) + 3. Reflecting across the x-axis negates outputs: −f(x); shifting up 3 adds 3 outside: −f(x) + 3. Distractors: A) f(−x) + 3 reflects across the y-axis instead. B) −f(x + 3) shifts horizontally, not vertically. C) −f(x) − 3 shifts down. E) f(−x) − 3 reflects the wrong axis and shifts down. Fix: x-axis reflection negates the whole function; vertical shift adds outside. [Understand]

25. E) (3, 1). Add the equations to eliminate y: (2x + y) + (x − y) = 7 + 2 → 3x = 9 → x = 3; then y = 7 − 2(3) = 1. Check: 3 − 1 = 2 ✓. Distractors: A) (1, 3) swaps the coordinates. B) (2, 3) fails both equations. C) (3, −1) has a sign error in y. D) (5, −3) satisfies neither equation. Fix: with opposite y-coefficients, add the equations to eliminate y in one step, then back-substitute. [Apply]

26. A) 64 ft. The vertex of h(t) = −16t² + 32t + 48 is at t = −b/(2a) = −32/(2·−16) = 1 s; h(1) = −16 + 32 + 48 = 64 ft. Distractors: B) 48 ft reports h(0), the initial height, not the max. C) 32 ft misreads the linear coefficient as the height. D) 80 ft adds 32 + 48 without evaluating at the vertex. E) 96 ft doubles the initial height. Fix: maximum of a downward parabola occurs at t = −b/(2a); substitute that t back to get the height. [Apply]

27. B) 21/5. Average rate of change = (f(6) − f(1))/(6 − 1) = (25 − 4)/5 = 21/5. Distractors: A) 21 forgets to divide by the change in x. C) 7/2 uses the wrong interval or averages differently. D) 5/21 inverts the ratio. E) 3 divides 21 by 7 instead of 5. Fix: average rate of change is Δy/Δx between the two endpoints — the slope of the secant line. [Apply]

28. C) sin θ. Using 1 − cos²θ = sin²θ, the expression is sin²θ / sin θ = sin θ. Distractors: A) cos θ misapplies the Pythagorean identity. B) csc θ inverts the result. D) tan θ comes from dividing by cos θ. E) 1 cancels incorrectly, treating sin²θ/sin θ as 1. Fix: replace 1 − cos²θ with sin²θ first, then cancel one factor of sin θ. [Apply]

29. D) no real solutions. The discriminant is b² − 4ac = (−4)² − 4(1)(7) = 16 − 28 = −12 < 0, so there are no real solutions (two complex conjugates). Distractors: A) and B) require a positive discriminant. C) requires discriminant = 0. E) infinitely many never occurs for a genuine quadratic. Fix: the sign of b² − 4ac decides: positive → two real, zero → one repeated, negative → none real. [Analyze]

30. A) It touches the x-axis at x = −2 and crosses at x = 3. An even-multiplicity zero (x = −2, mult 2) makes the graph touch and turn; an odd-multiplicity zero (x = 3, mult 1) makes it cross. Distractors: B) reverses which zero touches and which crosses. C) treats both as odd. D) treats both as even. E) invents an extra zero at x = 0 that the factored form does not provide. Fix: even multiplicity → bounce (touch); odd multiplicity → pass through (cross). [Analyze]

31. E) x ≥ 4. (f ∘ g)(x) = √(x − 4) requires x − 4 ≥ 0, so x ≥ 4. Distractors: A) all reals ignores the radical. B) x ≥ 0 uses the domain of √x without shifting. C) x ≤ 4 reverses the inequality. D) x > 4 wrongly excludes the endpoint 4, where √0 = 0 is defined. Fix: for √(inner), require inner ≥ 0 (endpoint included) and solve. [Apply]

32. B) vertical, length 10. In x²/9 + y²/25 = 1 the larger denominator (25) sits under y², so the major axis is vertical with semi-axis a = √25 = 5 and full length 2a = 10. Distractors: A) uses the smaller denominator and wrong orientation. C) right length but horizontal orientation. D) length 25 forgets to take the square root and double. E) uses √9 = 3 for the semi-axis. Fix: the larger denominator marks the major axis; its length is 2√(that denominator). [Understand]

33. C) horizontal compression by a factor of 1/2. Replacing x with 2x inside f speeds the input, compressing the graph horizontally toward the y-axis by a factor of 1/2. Distractors: A) a stretch by 2 comes from f(x/2), not f(2x). B) and D) describe vertical changes, which come from a coefficient outside f. E) a horizontal shift comes from f(x − 2), not f(2x). Fix: f(bx) with b > 1 compresses horizontally by 1/b; the effect is the reciprocal of the coefficient. [Understand]

34. D) x = 6. Isolate: 1/x = 1/2 − 1/3 = 3/6 − 2/6 = 1/6, so x = 6. Check: 1/6 + 1/3 = 1/6 + 2/6 = 3/6 = 1/2 ✓. Distractors: A) 1/6 reports 1/x instead of x. B) 5 comes from subtracting denominators. C) 1 mishandles the fraction subtraction. E) −6 sign error. Fix: combine the constant fractions with a common denominator first, then reciprocate to solve for x. [Apply]

35. A) π. The period of sin(Bx + C) is 2π/|B|; here B = 2, so the period is 2π/2 = π. The amplitude 3 and phase shift −π do not affect the period. Distractors: B) 2π ignores the factor 2. C) π/2 divides by B². D) 4π multiplies by 2 instead of dividing. E) 3π uses the amplitude 3. Fix: period depends only on the coefficient of x: 2π/|B|. [Apply]

36. E) 11 − 10i. FOIL: (3 + 2i)(1 − 4i) = 3 − 12i + 2i − 8i² = 3 − 10i − 8(−1) = 3 − 10i + 8 = 11 − 10i. Distractors: A) 3 − 8i drops the outer/inner terms. B) 11 + 10i has the imaginary sign wrong. C) −5 − 10i uses i² = +1. D) 3 − 10i forgets to convert −8i². Fix: multiply as binomials, then replace i² with −1 and combine real and imaginary parts. [Apply]

37. B) 10 g. In 18 years there are 18/6 = 3 half-lives, so the amount is 80·(1/2)³ = 80/8 = 10 g. Distractors: A) 20 g stops after 2 half-lives. C) 5 g runs 4 half-lives. D) 40 g runs only 1 half-life. E) 26.7 g divides by 3 linearly instead of halving repeatedly. Fix: number of half-lives = elapsed time ÷ half-life; multiply the start by (1/2) that many times. [Apply]

38. C) 2x + h. Expand: [f(x+h) − f(x)]/h = [(x + h)² − x²]/h = [x² + 2xh + h² − x²]/h = (2xh + h²)/h = 2x + h. Distractors: A) 2x drops the h before it can be canceled properly (that is the limit, not the quotient). B) 2x + h² fails to divide h² by h. D) x + h forgets the factor of 2 from the middle term. E) 2xh cancels incorrectly. Fix: expand (x + h)², subtract x², then divide every remaining term by h. [Apply]

39. D) y = 3 sin x − 1. Amplitude 3 (half of 2 − (−4) = 6) and midline y = −1 give y = 3 sin x − 1; it passes through (0, −1) rising to a max of 2 at x = π/2, matching sine. Distractors: A) sin x + 3 has amplitude 1 and the wrong midline. B) 3 sin x + 1 uses midline +1. C) −3 sin x − 1 is reflected, so it falls from (0, −1). E) 3 cos x − 1 starts at its maximum at x = 0, not on the midline. Fix: amplitude = (max − min)/2, midline = (max + min)/2; sine starts on the midline rising, cosine starts at a peak. [Analyze]

40. A) x < −2 or x > 3. Factor: x² − x − 6 = (x − 3)(x + 2) > 0. The product is positive outside the roots −2 and 3, so x < −2 or x > 3. Distractors: B) −2 < x < 3 is where the product is negative (< 0). C) and D) use wrong roots (−3 and 2). E) x > 3 only omits the left branch. Fix: find the roots, then a "> 0" parabola opening up is positive outside the roots, negative between them. [Analyze]

41. B) 40√3/3 ft. The height is opposite the 30° angle and 40 ft is adjacent, so tan 30° = h/40, giving h = 40 tan 30° = 40·(1/√3) = 40√3/3 ≈ 23.1 ft. Distractors: A) 20 ft uses sin 30° = 1/2 as the ratio. C) 40√3 ft uses tan 60° (or multiplies by √3). D) 40 ft ignores the trig. E) 80 ft doubles. Fix: pick the ratio linking the known side to the unknown: opposite over adjacent is tangent. [Apply]

42. E) (−1, 2). A function decreases where its graph falls; between the local maximum at x = −1 and the local minimum at x = 2 the graph descends, so it decreases on (−1, 2). Distractors: A) (−∞, −1) and B) (2, ∞) are where it rises. C) (−1, ∞) and D) (−∞, 2) each mix an increasing part with the decreasing part. Fix: decreasing = falling from left to right, which happens between a max (on the left) and the next min (on the right). [Analyze]

43. C) (x + 1)² + (y − 4)² = 25. The radius is the distance from center (−1, 4) to (2, 0): √((2 + 1)² + (0 − 4)²) = √(9 + 16) = 5, so r² = 25 and the equation is (x + 1)² + (y − 4)² = 25. Distractors: A) flips the center signs. B) uses r = 5 as r² (should be 25). D) flips signs and uses r for r². E) 100 squares the radius twice. Fix: standard form uses (x − h)² + (y − k)² = r²; find r as a distance, then square it. [Apply]

44. D) x = 3. log(x − 3) is defined only when x − 3 > 0; as x → 3⁺ the argument → 0⁺ and the log → −∞, giving a vertical asymptote at x = 3. Distractors: A) y = 3 and C) y = 0 are horizontal lines; logs have vertical asymptotes. B) x = 0 is the asymptote of log x before the shift. E) x = −3 has the shift direction backward. Fix: a log's vertical asymptote sits where its argument equals 0; solve x − 3 = 0. [Understand]

45. B) x = 3 and x = −5/3. |3x − 2| = 7 splits into 3x − 2 = 7 → x = 3, and 3x − 2 = −7 → 3x = −5 → x = −5/3. Distractors: A) x = 3 only keeps one case. C) x = 3, 5/3 gets the sign of the second root wrong. D) x = −3, 5/3 mishandles both. E) x = 9, −5/3 adds 7 to 2 before dividing. Fix: |A| = c (with c > 0) yields two equations, A = c and A = −c; solve each. [Apply]

46. A) $14,450. Depreciating 15% per year multiplies by 0.85 annually: 20,000·(0.85)² = 20,000·0.7225 = $14,450. Distractors: B) $14,000 subtracts a flat 30% (15% × 2), treating it as linear. C) $17,000 applies 15% just once. D) $13,000 subtracts 35%. E) $15,000 rounds arbitrarily. Fix: a constant percent change compounds — multiply by (1 − rate) once per year, not subtract a flat total. [Apply]

47. E) f(x) = x³ + 1. A one-to-one function passes the horizontal-line test. The cubic x³ + 1 is strictly increasing, so each output comes from exactly one input. Distractors: A) x², B) |x|, and C) x² − 4 each hit the same output for ±x (fail the horizontal-line test). D) the constant 4 sends every input to one output — as far from one-to-one as possible. Fix: one-to-one means no horizontal line meets the graph twice; strictly increasing (or decreasing) functions qualify. [Analyze]

48. D) 3/2. tan(π/4) = 1 and sin(π/6) = 1/2, so the sum is 1 + 1/2 = 3/2. Distractors: A) 1 uses only the tangent term. B) 1/2 uses only the sine term. C) √3/2 + 1 uses sin(π/3) instead of sin(π/6). E) √2/2 + 1/2 uses sin(π/4) for the first term. Fix: recall the exact values separately — tan(π/4) = 1, sin(π/6) = 1/2 — then add. [Apply]

Scaled Score Estimator

CLEP reports a 20–80 scaled score; ACE-recommended credit is granted at 50. This mock uses the approximation scaled ≈ 20 + 1.25 × (raw correct), which places the credit threshold at 24 of 48 correct (≈50%).

Raw correct (of 48) Approx. scaled score
0 20
4 25
8 30
12 35
16 40
20 45
24 50 ← ACE credit threshold
28 55
32 60
36 65
40 70
44 75
48 80

Intermediate raw scores interpolate (each additional correct answer ≈ +1.25 scaled points). Disclaimer: CLEP's exact raw-to-scaled conversion is proprietary and varies by form; this table is an approximation for self-assessment only, not an official predictor.

Score summary

Your running multiple-choice score appears in the bar below. Self-score the free-response section with the rubrics in the answer key, then use the diagnostic table to target review.

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