I need help with these two please and no links

Convert the cartesian equation (x 2 + y 2)2 = 4(x 2 - y 2) to a polar equation. choices: r4 = -4r2 r2 = 4cos2θ r2 = 4sin2θ

Aregular hexagon rotates counterclockwise about its center. it turns through angles greater than 0° and less than or equal to 360°. at how many different angles will the hexagon map onto itself?

Use the x-intercept method to find all real solutions of the equation. -9x^3-7x^2-96x+36=3x^3+x^2-3x+8