Solve Y=2usinθ/gcosdelta

$$Y = \frac { 2 u \sin \theta } { g \cos \delta }$$

Solve for Y

$$Y=\frac{2u\sin(\theta )}{g\cos(\delta )}$$

$$g\neq 0\text{ and }\nexists n_{1}\in \mathrm{Z}\text{ : }\delta =\pi n_{1}+\frac{\pi }{2}$$

Solve for g

$$\left\{\begin{matrix}g=\frac{2u\sin(\theta )}{Y\cos(\delta )}\text{, }&\nexists n_{1}\in \mathrm{Z}\text{ : }\theta =\pi n_{1}\text{ and }u\neq 0\text{ and }\nexists n_{1}\in \mathrm{Z}\text{ : }\delta =\pi n_{1}+\frac{\pi }{2}\text{ and }Y\neq 0\\g\neq 0\text{, }&\left(\left(\exists n_{1}\in \mathrm{Z}\text{ : }\theta =\pi n_{1}\text{ and }\nexists n_{1}\in \mathrm{Z}\text{ : }\delta =\pi n_{1}+\frac{\pi }{2}\right)\text{ or }u=0\right)\text{ and }Y=0\text{ and }\nexists n_{1}\in \mathrm{Z}\text{ : }\delta =\pi n_{1}+\frac{\pi }{2}\end{matrix}\right.$$