The length x of a rectangle is increasing at the rate of 5 cm/minute and the width y is increasing at the rate of 5 cm/minute. When x =2 cm and y = 2 cm, find the ratio of rates of change of perimeter to that of the area with respect to time.
Answer & explanation
Correct answer: option 1
dA/dt = x(dy/dt)+y(dx/dt)
dP/dt = 2(dx/dt +dy/dt)