Use the Given Transformation to Evaluate the Integral $$\begin{array} { l } u = y - x , v = y + x \\\quad \iint \cos \left( \frac { y - x } { y + x } \right) d x d y ,\end{array}$$

Multiple Choice

Use the given transformation to evaluate the integral.
- $$\begin{array} { l } u = y - x , v = y + x \\\quad \iint \cos \left( \frac { y - x } { y + x } \right) d x d y ,\end{array}$$
where $R$ is the trapezoid with vertices at $( 3,0 ) , ( 10,0 ) , ( 0,3 ) , ( 0,10 )$

A) $\frac { 91 } { 4 } \sin 2$
B) $\frac { 91 } { 2 } \sin 2$
C) $\frac { 91 } { 4 } \sin 1$
D) $\frac { 91 } { 2 } \sin 1$