There is a unique pair of positive real numbers satisfying the equations \[ x^4-6x^2y^2+y^4 = 8 \qquad\mbox{and}\qquad x^3y-xy^3 = 2\sqrt{3}. \]Determine $x$, writing your answer in the form $a\cos\theta$, with $\theta$ in degrees.
I use WA and the x value is $\sqrt(2+\sqrt(3))$
how do I convert to a*cos(theta)
I graphed it and I see 4 real solutions.
Oh, sorry, x and y must both be positive
https://www.desmos.com/calculator/a1oy7stjhb