Find all the antiderivatives of f(x)=ex+6x2−sinx.
Solution Since f is the sum of three functions, we use the Sum Rule. That is, we find the antiderivatives of each function individually and then add. f(x)=ex+6x−2−sinx
Since the antiderivatives of ex are ex+C1, the antiderivatives of 6x2 are −6x+C2, and the antiderivatives of sin x are −cos x+C3, the constant C in Example 2 is actually the sum of the constants C1, C2, and C3.
An antiderivative of ex is ex. An antiderivative of 6x−2 is 6⋅x−2+1−2+1=6⋅x−1−1=−6x
Finally, an antiderivative of sinx is −cosx. Then all the antiderivatives of the function f are given by F(x)=ex−6x+cosx+C
where C is a constant.