3. Solve the following, show your steps.
(a) \int \cos^2(\theta) \,d\theta
(b) \int \frac{\sin(x)}{\sec(x)} \,dx
(c) \int_0^{2\pi} \sin(\theta) \,d\theta
(d) \int_0^{\pi} \cos^2(\theta) \,d\theta + \int_\pi^{2\pi} \sin(\theta) \,d\theta
(e) \int_0^{2\pi} (\frac{1}{\theta}) \,d\theta
(f) \int_0^{\pi} \cos(\theta) \,d\theta + \int_\pi^{2\pi} \cos(\theta) \,d\theta
