Question

16 sin 10 sin 30 degrees sin 50 degrees sin 70 degree is equal to 1

Answer 1

sin10sin30sin50sin70
sin30sin50sin70sin10
1/2{sin70sin50}sin10
multiplying by 2 in numerator & denominator
1/4{2sin70sin50}sin10
1/4{sin120+sin20}sin10                    [sin120=-1/2]
1/4{-1/2+sin20}sin10
1/4{-sin10+2sin20sin10}
                 2

1/8{-sin10+sin30+sin10}
1/8{sin30}
1/8(1/2)
1/16  hence proved....