\left(1+2\cdot W\cdot\frac{C_2^2}{C_1^2}\right)^{0.5}\left(y\ \cos\left(C_3\right)\ +\ x\cdot\sin\left(C_3\right)\right)\ =\ \left(x^2+y^2\right)^{0.5}\cdot\left(1+2\cdot W\cdot\frac{C_2^2}{C_1^2}\right)\ -\ \frac{C_2^2}{C_1}