Decide, without calculation, if each of the integrals below are positive, negative, or zero. Let D be the region inside the unit circle centered at the origin. Let T, B, R, and L denote the regions enclosed by the top half, the bottom half, the right half, and the left half of unit circle, respectively.

? Positive Negative Zero  1. $\displaystyle \iint\limits_L x e^x \, dA$

? Positive Negative Zero  2. $\displaystyle \iint\limits_B x e^x \, dA$

? Positive Negative Zero  3. $\displaystyle \iint\limits_D x e^x \, dA$

? Positive Negative Zero  4. $\displaystyle \iint\limits_T x e^x \, dA$

? Positive Negative Zero  5. $\displaystyle \iint\limits_R x e^x \, dA$