Double integrate from cartesian to polar and then evaluated

[jimbo71]

Homework Statement

convert double integral from line one to polar integral and then evaluate
see problem 12 attachment

Homework Equations

y=rsinx
x=rcosx
r^2=x^2+y^2

The Attempt at a Solution

see problem 12 attachment
I calculate a area of zero. are my limits wrong and if so which ones, or did i make a mistake in the aritmatic, or something else?

 

[quantumdude]

You start to go wrong at the end of the 5th line. e^{-1} does not equal e.