4*9x4*3 whats the answer

How do i do this activity, is appreciated

When the solutions to each of the two equations below are graphed in the xy-coordinate plane, the graphs of the solutions intersect at two places. write the y-cordninates of the points of intersection in the boxes below in order from smallest to largest. y=2x y=x^2-3

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