Question 5 - A-Level Maths

Show that the equation $2 \tan ^ { 2 } \theta \sin ^ { 2 } \theta = 1$ can be written in the form $$2 \sin ^ { 4 } \theta + \sin ^ { 2 } \theta - 1 = 0 .$$
Hence solve the equation $2 \tan ^ { 2 } \theta \sin ^ { 2 } \theta = 1$ for $0 ^ { \circ } \leqslant \theta \leqslant 360 ^ { \circ }$.