1.

Sin20°sin40°sin60°sin80°=3/16

Answer»

Hey !!!

from LHS

sin20° sin40° sin60° sin80°

sin60° sin20 sin40° sin80°

3/2 sin20° sin40° sin80°

we KNOW a defined rule ⚜

SINX sin ( 60° - x ) sin ( 60° + x) =
\boxed{ \frac{1}{4} sin3x}

similarly

hence,

LET x = 20 °

then

= √3/2 × 1/4sin 3*20°

= √3/2 ×1/4sin60°

√3/2*√3/2 ×1/4


= 3/16 LHS = RHS prooved ♻

_____________________________

Hope it HELPS you !!!!

\underline{rajukumar111}



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