math
posted by susan on .
side of the cube increasing at rate of 6 cm/s. find the rate of increase of the volume when the length of a side is 9 cm.[ans 1458cm^3/s]
my answer:
~729x6=4374cm^3/s
i need some1 show me the calculation if im wrong.

V = x^3
dV/dx = 3 x^2
so
dV/dt = 3 x^2 dx/dt
dV/dt = 3 * 81 * 6 = 1458 cm^3/s