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 x be the length of a sideand V bethe volume of the cube. Then,
V = x3.
∴ (By chain rule)
Thus, when x = 10 cm,
Hence, the volume of the cube is increasingat the rate of 900 cm3/s when the edge is 10 cm long.