1. cos^2(44°) + cos^2(46°)
2. sin2 (79°) + sin2 (53°) + sin2 (37°) + sin2 (11°)
3. Solve the equation for x. Use n as an integer constant.
then use the formula to simply your answer.
On #2. A similar strategy can be used like #1. Rewrite some of the angles into sums or differences and simply.
On #3. When you get down to , think about what angles give you such value. It is going to be something "special".