Question

find the critical numbers of the function 2t^(2/3)+t^(5/3)

Answer 1

Those would be where the derivative is zero.

(4/3)t^(-1/3) + (5/3) t(2/3) = 0
t^(-1/3)*[(4/3) + (5/3)t] = 0

t = 0 or -4/5