Evaluate any two of the following integrals using contour integration. Clearly show the contour that you are using in each case, show all your steps, and state clearly any assumptions or theorems you are using. If any poles lie on the real axis, evaluate instead the principal part of the integral. If you attempt more than two of the integrals, the highest two marks only will be counted. (a) (b) L sin(3x) x+2x+5 dx 2 1 cos +2 21/3 2+2 -do -dx (c) S