How do you solve f(x)=2x^2-3x using the difference quotient

How do you use the elimination method for this question? explain, because i really want to understand!

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

The description below represents function a and the table represents function b: function a the function is 5 more than 3 times x. function b x y −1 2 0 5 1 8 which statement is correct about the slope and y-intercept of the two functions? (1 point) their slopes are equal but y-intercepts are not equal. their slopes are not equal but y-intercepts are equal. both slopes and y intercepts are equal. neither slopes nor y-intercepts are equal.