If a snowball melts so that its surface area decreases at a rate of 3 cm2/min, find the rate at which the diameter decreases when the diameter is 12 cm. (Give your answer correct to 4 decimal places.)

π

relating diameter(x) to radius:

π

π

=-.039788

to 4 decimal places,

I got the http://www.webassign.net/wastatic/common/img/cross.png.