Question

Prove that : $sin{15}^o=\frac{\sqrt{3}-1}{2\sqrt{2}}$

Answer 1

$\sin {15}^o=\sin ({45}^o-{30}^o)=\sin {45}^o\cos {30}^o-\cos {45}^o\sin {30}^o=\frac{1}{\sqrt{2}}\ast \frac{\sqrt{3}}{2}-\frac{1}{\sqrt{2}}\ast \frac{1}{2}=\frac{\sqrt{3}-1}{2\sqrt{2}}$