The Total solution for NCERT class 6-12
An edge of a variable cube is increasing at the rate of 3cm/s. How fast is the volume of the cube increasing when the edge is 10 cmlong?
Let┬аx┬аbe the length of a sideand┬аV┬аbethe volume of the cube. Then,
V┬а=┬аx3.
тИ┤┬а(By chain rule)
Thus, when┬аx┬а= 10 cm,
Hence, the volume of the cube is increasingat the rate of 900 cm3/s when the edge is 10 cm long.