so does that mean that 1/3 applies to the first integral. And also the integral is 0, 9 on the first integral and 0,3 on the second..... how does that work out?
Originally Posted by TheEmptySet
let
and don't forget the variable of integration is a dummy variable.
You are given that which, since we can always change a dummy variable, is the same as . To integrate , let u= 3x so x= u/3 as TheEmptySet suggested. Then dx= (1/3)du. When x= 0, u= 0. When x= 3, u= 9. The integral becomes