First, we evaluate the inner integral with respect to y: ∫−xxe−x2dy=e−x2∫−xxdy=e−x2[y]−xx=e−x2(x−(−x))=e−x2(2x)=2xe−x2 Now, we evaluate the outer integral with respect to x: ∫022xe−x2dx Let u=−x2. Then du=−2xdx, so −du=2xdx. When x=0, u=−02=0. When x=2, u=−22=−4. Thus, the integral becomes:
∫0−4eu(−du)=−∫0−4eudu=∫−40eudu=[eu]−40=e0−e−4=1−e−4=1−e41