2 Attachment(s)

Rationalizing Substitutions

[IMG]file:///C:/Users/Karina/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif[/IMG]Attachment 18198

This is the equation I am having trouble with. I think that 2sin(u) is what I need to use for x. Once I substitute everything in and begin to do all the steps, I get stuck. I'll show what I have so far. If I done something wrong please feel free to correct me. I also know what my answer should be, but I don't want just the answer I need help understanding how to get the answer.

Attachment 18200

[IMG]file:///C:/Users/Karina/AppData/Local/Temp/msohtmlclip1/01/clip_image006.gif[/IMG]