Question

The length of a rectangle is increasing at a rate of 4 cm/s and its width is increasing at a rate of 7 cm/s. When the length is 14 cm and the width is 4 cm, how fast is the area of the rectangle increasing?

Answer 1

using the A=lw we have dA/dt=? + ? dl/dt

Answer 2

DA=(ldl)(wdw)

Answer 3

so that would be 14 and 4?

Answer 4

chain rule
(14 dl)(4 dw)

Answer 5

but how do i apply the chain rule??

Answer 6

You are given values of dl and dw.

Answer 7

yes....??

Answer 8

dl=4
dw=7

Answer 9

chaguanas I need your help