Question

if f(x+3)=2x2 -3x-1 find the value of f(x+1)​

Answer 1

Answer:

f(x) = x^3 +x^2 -2x

First we will calculate the derivative of f(x)

f'(x) = 3x^2 + 2x -2

Now we will substitute with x=1

f'(1) = 3+2-2 = 3

Now we will substitute with x=-1

f'(-1) = 3-2-2= -1

Then f'(1) + f'(-1)= 3 + -1= 2