Question 15
Let $C_1$ be the curve with $y=x^2$. Suppose that $C_1$ is rotated anticlockwise by $75^\circ$ to obtain the curve $C_2$. It is known that the equation of $C_2$ can be written in the form $(8-4\sqrt3)x^2+By^2+Cx+Dy+Exy=0$. Find $\left\lfloor(8-4\sqrt3)+|B|+|C|+|D|+|E|\right\rfloor$.