Question

What is `f(x) = int (3x+5)^3-x dx` if `f(1)=-5`?

Answer 1

just integrate

Explanation:

`f(x) = int((3x+5)^3-x)dx`

`=> int(3x+5)^3dx - intxdx`

`=> f(x) = 1/12(3x+5)^4 - x^2/2 + c`- 1
where c is a constant
now placing `x=1` and `f(1)=-5`

`=> -5 = 1/12(3+5)^4 - 1/2 + c`

find c place it back in equation 1

you can find f(x)
hope u find it helpful :)