Solving Integrals Using a Known Mac Series (Sin(x))

[HolyDesperado]

Homework Statement

Assume that sin(x) equals its Maclaurin series for all x. Use the Maclaurin series for sin(7x^2) to evaluate the integral https://webwork.math.lsu.edu/webwork2_files/tmp/equations/f4/767c0643696d085d77f9a697294a311.png

Your answer will be an infinite series. Use the first two terms to estimate its value.

Homework Equations

The Attempt at a Solution

http://img27.imageshack.us/img27/5028/mathhelp2k.jpg

After the final step in the picture, I plugged in n=0 and 1 to get my 0th and 1st terms, then I added them together and I got: 0.754110411. This is wrong, however.. can someone please help me diagnose this problem?

 

[yyat]

You forgot powering the 7, you need 7^(2n+1).

 

[HolyDesperado]

Thank you, I see my error now and the suggestion lead me to a correct answer.