Calculus question

Question

The length of a rectangle is increasing at a rate of  8cm/s  and its width is increasing at a rate of 3 cm/s. When the length is 30cm and the width is  10cm how fast is the area of the rectangle increasing?

Answer (in cm^2/s):_____________

What is the answer in Cm^2/s ?

Answer 1

Well A = lw

dA/dt = l dw/dt + w dl/dt

l =30, w = 10, dl/dt = 8, dw/dt = 3