Hi, I was practising differentiation and came across a some what rather easy question which I could not do. Can any one direct me as usual. (this place is becoming my e-home). Mind you I am enjoying using LaTex converters haha. Q. The length L of a rectangle is decreasing at the rate of 3 cm/sec, and the width W is increasing at the rate of 2 cm/sec. Find the rate of change of the area when L = 15 cm and W = 8 cm. Thanks.