1. Simplify: sin^2(x)/sec^2(x)-1
2. Factor and simplify: cos^2(x)-sin^2(x)cos^2(x)
3. Perform the addition and simplify: 1/1+sinx + 1/1-sinx
4. Simplify: sec^4(x) + sec^2(x)-2
This shows how to simplify a variety of trigonometric expressions.