Evaluate the Integral $$2 \int _ { 0 } ^ { x / 2 } \sin ^ { 3 } \theta \cos ^ { 2 } \theta d \theta$$

Evaluate the integral. $$2 \int _ { 0 } ^ { x / 2 } \sin ^ { 3 } \theta \cos ^ { 2 } \theta d \theta$$