How do i solve this?

Question

For the function 𝑓(𝑥) = 3𝑥 5 − 5𝑥 3

find the global maximum and minimum on the closed interval [−1.2, 2]. This is all numbers such that −1.2 ≤ 𝑥 ≤ 2.

Answer 1

g(x) = 3x⁵ - 5x³

g(x) = x²(3x² - 5)

zeros at 0, ±√(5/3)

g'(x) = 15x⁴ - 15x²

g'(x) = 15x²(x² - 1)

In the interval [-1.2, 2] maximum at -1 and minimum at 1.