Find an Equation of the Tangent Plane to the Surface $x = \cos u \sin v$

Essay

Find an equation of the tangent plane to the surface with parametric equations $x = \cos u \sin v$ , $y = \sin u \sin v$ , $z = \cos v$ at the point $\left( \frac { 1 } { 2 } , \frac { 1 } { 2 } , \frac { 1 } { \sqrt { 2 } } \right)$ .