Unit 4: Applications of Derivatives
15
out of 18
82% Correct
Estimated AP Score: 4
β
15
Correct
β
3
Incorrect
β±οΈ
28m
Time Used
π
1.6m
Avg per Q
Question Review
β
CorrectQ1 Β· 1m 12s
Related Rates
A spherical balloon is inflated at a rate of 10 cmΒ³/s. Find the rate of change of the radius when r = 5 cm.
Your answer: A β
β IncorrectQ5 Β· 2m 45s
Optimization
A farmer has 120m of fencing to enclose a rectangular field alongside a river. Find the maximum area.
Your answer: B β Correct: C
Explanation: Only 3 sides need fencing (river on one side). If width = x, then length = 120 - 2x. Area = x(120-2x). Take derivative and set to 0: 120-4x=0, x=30. Max area = 30Γ60 = 1800 mΒ².
β
CorrectL'HΓ΄pital's Rule
Evaluate lim(xβ0) (eΛ£ - 1)/x