Question

The value of 6sin20-8sincube20is=

Answer 1

$2(3 \sin(20) - 4( { \sin(20) })^{3} ) \\ = 2( \sin(3 \times 20) ) \\ = 2 \sin(60 ) = 2 \times \frac{ \sqrt{3} }{2} \\ = \sqrt{3}$