Integrating with Trig Identities

These questions use trig identities to make integrals possible: ${\sin }^{2}x$ and ${\cos }^{2}x$ by double angles, ${\tan }^{2}x$ by ${\sec }^{2}x-1$, and products by products to sums. They start easy and get harder. Stuck? Tap Show a hint for one step at a time.