Question

Find the value of sin15degree

Answer 1

sin 15°
=sin(45°-30°)
=sin45°cos30°-cos45°sin30°
=1/√2×√3/2-1/√2×1/2
=√3/2√2-1/2√2
=(√3-1)/2√2

Answer 2

Sin15° = Sin(45° - 30°)
Sin(A - B) = SinA CosB - CosA SinB
Sin(45° - 30°) = Sin45° Cos30° - Cos45° Sin30°
    
                       = $\frac{1}{\sqrt2} . \frac{\sqrt3}{2} - \frac{1}{\sqrt2} . \frac{1}{2}$
 
                       = $\frac{\sqrt3 - 1}{2\sqrt2}$