a y = ( c o s θ 0 + a x 2 s i n θ 0 ) 2 − c o s 2 θ 0 , {\displaystyle {\begin{aligned}ay{\rm {=}}{\left({\rm {\ cos\ }}{\theta }_{0}{\rm {+}}{\frac {ax}{\rm {2}}}{\rm {\ sin\ }}{\theta }_{0}\right)}^{\rm {2}}-{\rm {cos}}^{\rm {2}}{\theta }_{0},\end{aligned}}}
