Question

Let f(x) = 2x2 + x – 6
(A) find f'(x)
(b) Find the value of x for which f'(x)=0

Answer 1

(a) f(x) = 4x+1 (b) x = -1/4

Step-by-step explanation:

Given that,

`f(x) = 2x^2 + x - 6`

(a) We need to find f'(x).

`f'(x)=(d)/(dx)(2x^2+x-6)\\\\=4x+1`

(b) We need to find the value of x when f'(x) =0

Put f'(x) = 0

4x+1 = 0

`4x=-1\\\\x=(-1)/(4)`

So, the value is -1/4 when f'(x) = 0.