Question

Find the rate of change of area of the square in m/s with respect to its side when the sides, s, is 4m each.

Answer 1

$$A=A(s)=s^2$$

$$A'=(s^2)'=2s$$

$$A'(4)=2(4)=8$$

When $s=4\ m,$ the rate of change of area is $8\ m^2/m.$