Answer:

Explanation:
For instantaneous rate of change, we can use differentiation and differentiate 'g' wrt 't'.
Given,

According to power constant rule; d(ax^n)/dx = n*ax^(n-1). And differentiation of a constant is 0.
Differentiating 'g' wrt 't'

Instantaneous rate of change at t = 2,

The instantaneous rate of change of g (5t² - 1) is 20.