Question a) Sketch the region of integration for the following integrals \text { (c) } \int_{2}^{4} \int_{\pi / 2}^{5 \pi / 4}\left(r^{2}+1\right) r d \theta d r \text { (d) } \int_{0}^{\pi / 4} \int_{0}^{1 / \cos \theta} \sin \theta r d r d \theta \int_{0}^{5} \int_{-2}^{x+1}\left(x^{2}+y^{2}\right) d y d x \int_{0}^{3} \int_{y+1}^{4} \sin (x y) d x d y