Question -
Answer -
The two numbers are x and y suchthat x + y = 60.
⇒ y = 60 − x
Let f(x) = xy3.
∴By second derivative test, x = 15 is apoint of local maxima of f. Thus, function xy3 ismaximum when x = 15 and y = 60 − 15 = 45.
Hence, the required numbers are 15 and 45.