I worked on this homework problem, went to class and when the teacher went over it he got a different answer than I did and set his equation up differently. I erased my work and started over, but the way he set up his equation didn't make sense to me and when I worked through it I got negative areas. I don't remember my initial process since I erased it to follow my teachers instruction but I believe I initially got 1/25, which I'm not sure is right either but when I use his version I get -9/5 and he expects 3/5 from it. I'm including pictures of the assignment, my initial footwork, and my graph, along with the equation and answer I copied off the board to day and the way I worked it out. Any help seeing why his version works and/or how it turns out to 3/5 or just where I can look at where I might have gone wrong would be an extra help. This was actually due today but he gave the class an extension until first thing in the AM. So I need to figure this out ASAP. Thanks in advance for any help.

These are the instructions for the problem.

This is the problem #7.

Finding the points of integration.

My graph, replica from my graphing calculator.

Teachers version of equation and answer.

Me working through first integration of teachers equation.

Working through the second integration of teachers equation.

Adding the results from the integrations.

I've never posted pictures on here and when I wrote out my work I wasn't expecting to post it online so I hope you can read and see everything I'll check once it posts to see if it works.