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

1 Answer
Jan 21, 2018

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 :)