Thread: Quick integral question.

1. Quick integral question.

I have been able to do most of the problems since reading the book but this one is giving me trouble. Thanks.

2. Originally Posted by xcelxp
I have been able to do most of the problems since reading the book but this one is giving me trouble. Thanks.

let u = 1 + lnx <--> du = 1/x dx --> dx = x du

INT {a,b} 1/u du = ln|u| for {a,b} = ln|1 + lnx| for {1,e^3} = ln|1 + lne^3| - ln|1 + ln1| = ln4 - ln(1) = ln4