6.7 Try It Problems [STARTS AT 5:59] INSTRUCTOR: For our next example, we want to find the antiderivative of 4 divided by e to the 3x dx. You can rewrite this as the antiderivative of 4e to the negative 3x dx and let u equal negative 3x. Then du is negative 3 dx. And negative 1/3 du equals dx. You can apply this substitution to say this integral is equal to negative 4/3 antiderivative of e to the u du. Now I know the antiderivative of e to the du will just be e to the u. So this becomes negative 4/3 e to the u plus c. And since we said u is negative 3x, this result of our antiderivative is negative 4/3 e to the negative 3x plus c. And I would always recommend taking the derivative of your result from an antiderivative. You should get what you began with. These are up to a constant. These are inverse operations. [ENDS AT 7:40]