Find the Derivative $\frac { d } { d t } \left[ \mathbf { r } ( 6 t ) \cdot \mathbf { r } \left( t ^ { 4 } \right) \right]$

Short Answer

Find the derivative $\frac { d } { d t } \left[ \mathbf { r } ( 6 t ) \cdot \mathbf { r } \left( t ^ { 4 } \right) \right]$