Why can’t we use the right angle as our reference angle when using trig ratios?

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

Select the correct answer from each drop-down menu. consider the following polynomials equations. 3x^2(x-1) and -3x^3+ 4x^2-2x+1 perform each operation and determine if the result is a polynomial. is the result of a + b a polynomial? yes or no is the result of a - b a polynomial? yes or no is the result of a · b a polynomial? yes or no

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.