Question

If f is defined by f (x) = x² – 4x + 7, show that f’ (5) = 2 f’ (7/2)

Answer 1

Here, polynomial function f(x) = x² - 4x + 7, and f(x) it's value at x = 5 and x = 7/2. On using the formula

Here the function is differentiable at x = 5 and its value 6.

So, f'(5) = 2f'(7/2) = 6

Hence the proved.