2022 AP Calculus AB Free-Response Questions — Full Solutions
Complete worked solutions with scoring breakdowns for all 6 FRQs
Questions 1–2 (Part A, 30 min) permit a graphing calculator. Questions 3–6 (Part B, 60 min) do not.
Question 1
Calculator OKToll Plaza Arrival Rate
Rate, Average Value & Optimization
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Set up the accumulation integral
AP Scoring — 1 Point
Answer
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Apply the average value formula
Evaluate with a calculator
AP Scoring — 2 Points
**P2**: Correct answer, 375.537 (accept 375.536–375.538).
Answer
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Differentiate A(t)
Evaluate at t = 1
Conclude
AP Scoring — 2 Points
**P2**: Correct conclusion ("increasing") tied to the sign of .
Answer
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Find a, the time the line first forms
Find where N could be maximized
Evaluate N at the maximizing time
(compare to , confirming the interior critical point gives the larger value)
Conclude
AP Scoring — 4 Points
**P2**: Considers , i.e. the second crossing , as the critical point of interest.
**P3**: A justification comparing at the critical point to (global argument), or a sign analysis of around .
**P4**: Correct final answer, 71 vehicles, with supporting work.
Common mistake: A common shortcut error: forgetting that the domain is restricted to $[a,4]$ and instead searching for a maximum over the full $[0,5]$ range covered by $A(t)$ — the question only asks about the line's length up to $t=4$.
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Question 2
Calculator OKArea and Volume Between f and g
Area & Volume
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Find B
Set up and evaluate the area integral
AP Scoring — 2 Points
**P2**: Correct answer, 3.604 (accept 3.603–3.605).
Answer
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Write h(x) and differentiate
Evaluate at x = -0.5
Conclude
AP Scoring — 2 Points
**P2**: Correct conclusion ("decreasing") tied to the sign of .
Answer
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Set up the volume integral
Evaluate with a calculator
AP Scoring — 3 Points
**P2**: Correct limits to .
**P3**: Correct answer, 5.340 (accept 5.339–5.341).
Answer
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Write the cross-sectional area as a function of x, then apply the chain rule
Substitute values at x = -0.5
AP Scoring — 2 Points
**P2**: Correct answer, (accept to ).
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Question 3
No CalculatorAnalyzing a Function from its Derivative Graph
Graph Analysis & Curve Sketching
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Answer
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Find f(0) using the semicircle's signed area
Find f(5) using the triangle's area
AP Scoring — 2 Points
**P2**: .
Answer
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Relate inflection points to local extrema of f'
Locate local extrema of f'
Conclude
AP Scoring — 2 Points
**P2**: Justification tied to having a local extremum (or changing sign) at each location.
Answer
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Set up g'(x) = f'(x) - 1
Compare f'(x) to 1 on each piece
On (line, slope 1, from to ): for .
On (line from to ): throughout, so here.
Conclude
AP Scoring — 3 Points
**P2**: Correctly comparing to 1 on each piece of the domain.
**P3**: Correct interval, , with supporting analysis.
Answer
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Identify the critical point
Evaluate g(5)
Confirm against the endpoints
AP Scoring — 2 Points
**P2**: Correct value, .
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Question 4
No CalculatorMelting Ice Sculpture — Table Data
Rate & Data from Tables
Open this question on its own pageValues of r′(t)
| t (days) | 0 | 3 | 7 | 10 | 12 |
|---|---|---|---|---|---|
| r′(t) (centimeters per day) | −6.1 | −5.0 | −4.4 | −3.8 | −3.5 |
Answer
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Set up the difference quotient
State the units
AP Scoring — 2 Points
**P2**: Correct units.
Answer
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Set up the IVT argument
Compare -6 to the endpoint values
Conclude
AP Scoring — 2 Points
**P2**: Correct comparison and conclusion citing the IVT.
Answer
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Set up the right Riemann sum
Substitute and compute
AP Scoring — 2 Points
**P2**: Correct answer, .
Answer
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Differentiate V with respect to t
Substitute values at t = 3
Simplify
AP Scoring — 3 Points
**P2**: Correct substitution, including using the table value for .
**P3**: Correct final answer, (or its decimal equivalent).
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Question 5
No CalculatorA Differential Equation with a Square-Root Factor
Differential Equations
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Follow the slope field from (1, 2)
AP Scoring — 1 Point
Answer
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Find the slope at (1,2)
Write the tangent line and approximate
AP Scoring — 2 Points
**P2**: Correct approximation, .
Answer
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Relate concavity to tangent-line approximation
Conclude
AP Scoring — 1 Point
Answer
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Separate variables
Integrate both sides
Apply the initial condition f(1) = 2
Solve for y
AP Scoring — 3 Points
**P2**: Correct antiderivatives on both sides, with constant of integration correctly evaluated using .
**P3**: Correctly solves for to reach the final closed form.
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Answer
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Differentiate x_P(t)
AP Scoring — 1 Point
Answer
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Differentiate v_Q(t)
Compare signs of v_Q and a_Q for t > 0
Conclude
AP Scoring — 3 Points
**P2**: Correct sign analysis showing and have opposite signs.
**P3**: Correct conclusion — for **all** , with justification.
Answer
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Set up position as initial position plus accumulated change
Evaluate the integral
AP Scoring — 2 Points
**P2**: Correct final answer, .
Answer
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Find the limiting positions
Compare
Conclude
AP Scoring — 2 Points
**P2**: Correct conclusion (particle ) with a reason comparing the two limits.
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Gary Chang
Calculus Educator5+ Years of Calculus Teaching Experience | AP Calculus Specialist. Dedicated to helping students master calculus through step-by-step logic and clear visualizations.
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