WeBWorK 6 (3.1-3.4) and assignment

WRITTEN ASSIGNMENT 6: MONOTONICITY,

CONCAVITY, & APPLICATIONS

CALCULUS I, FALL 2022 MATH 1210-090

INSTRUCTOR: WILL FELDMAN

Name: uID:

Problem 1. Consider the function

f(x) = x5/4 − 8x1/4

(a) Find f ′(x).

(b) Find the critical points of f(x) and state whether each one is a sta- tionary point or a singular point. Hint: use a common denominator to write the function in the form Ax+B

Cx1/D for some appropriate con- stants.

1

2 CALCULUS I, FALL 2022 MATH 1210-090 INSTRUCTOR: WILL FELDMAN

(c) Use the First Derivative Test to classify each critical point found in (b) as a local minimum, local maximum, or neither.

Problem 2. A manufacturer is making cylindrical cans with radius r and height h. Corporate says the volume of the cans must be 500 mL (i.e. cm3) exactly. Corporate also says the base of the can should be made out of a “smart wifi-enabled” material that tracks consumer can use patterns. This material costs 3 times as much as the material used for the sides and top of the can. What are the dimensions r and h of the can that minimize the total cost.