Integeral: Trig Substitution help

__http://www.sitmo.com/gg/latex/latex2...7D%7D%7Bx%7Ddx__

I have this equation

So I refer to a triangle and use these values for substitution.

http://www.codecogs.com/eq.latex?%5C...x%5E%7B2%7D%7D = 5 cos(x)

x = 5 sin(x)

dx = 5 sin(x) = 5 cos(x)

I ended up having something like this.

http://www.sitmo.com/gg/latex/latex2...Csin%28x%29%7D

I canceled the 5 sin(x)s leaving me with

integral(5 cos x) = - 5 sin x + c

I looked at the triangles and got back.

x/5 + c

Then I looked back at the book for answers and I was way way way off.

What did I do that was totally wrong?