The free-response questions are part of the AP Calculus BC exam.
Section II is divided into Part A and Part B.
Part A requires a graphing calculator and Part B does not.
Section II, Part A
Question 1
Scenario: A tank with a height of 10 feet.
The area of horizontal cross-section at height ( h ) is given by a function ( A(h) ).
Function ( A(h) ) is continuous and decreases as ( h ) increases.
Data is provided in a table.
Tasks:
(a) Use a left Riemann sum with three subintervals to approximate the volume of the tank. Indicate units.
(b) Determine if the approximation overestimates or underestimates the volume. Explain why.
(c) Model the area with function ( f ) and find the tank's volume. Indicate units.
(d) Water is pumped into the tank. When water height is 5 feet and increasing at 0.26 ft/min, find the rate of volume change using the model from part (c). Indicate units.
Question 2
Polar Curves:
Two curves are given: ( r = f(\theta) = 1 + \sin(\theta) \cos(2\theta) ) and ( r = \cos(\theta) ).
Define region ( R ) and ( S ) in the first quadrant.
Tasks:
(a) Find the area of region ( R ).
(b) Write an equation involving integrals to find ( \theta = k ) dividing ( S ) into equal areas.
(c) Write an expression for the distance ( w(\theta) ) between points ( (f(\theta), \theta) ) and ( (g(\theta), \theta) ). Find average value ( w_A ).
(d) Find ( \theta ) where ( w(\theta) = w_A ) and determine if ( w(\theta) ) is increasing or decreasing.
Section II, Part B
Question 3
Function: ( f ) is differentiable on ([6, 5]) and ( f'(2) = 7 ).
Tasks:
(a) Find ( f(6) ) and ( f(5) ).
(b) Identify intervals where ( f ) is increasing. Justify.
(c) Find absolute minimum of ( f ) on ([6, 5]). Justify.
(d) Evaluate ( f'(3) ) and determine existence.
Question 4
Scenario: Potato cooling from initial temperature 91°C.
Modeled by ( H(t) ) with differential equation ( \frac{dH}{dt} = -\frac{1}{4}(H - 27) ).
Tasks:
(a) Tangent line at ( t=0 ) and approximate temperature at ( t=3 ).
(b) Use ( \frac{d^2H}{dt^2} ) to analyze if approximation is under/overestimate.
(c) Alternate model ( G(t) ) with different differential equation. Determine temperature at ( t=3 ).