Use the Chain Rule to Find $\frac { \partial w } { \partial s }$

Short Answer

Use the Chain Rule to find $\frac { \partial w } { \partial s }$ where $s = 4 , t = 0$ .
$$w = x ^ { 2 } + y ^ { 2 } + z ^ { 2 } , \quad x = s t , \quad y = s \cos t , \quad z = s \sin t$$