Solve for missing sides of a right triangle using the pythagorean theorem of 6 and 11 and x

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).