show that sin 19 ° + sin 41 ° + sin 83 °= sin 23 ° + Sin 37 °+ sin 79 °
Open in App
Solution
RHS sin23 + sin 37 + sin 79 =2 sin (37 +23) /2 x cos (37- 23)/2 + sin79 =2 sin 60/2 x cos 14/2 + sin (90-11) =2 sin30 x cos 7 + cos 11 = 2 x 1/2 x cos (90 -83) + cos 11 = sin 83 + cos 11
LHS sin 19 + sin41 + sin83 = sin (19 +41) + sin 83 = 2 sin (14+19) /2 x cos (41-19) /2 + sin 83 = 2 sin 60/2 x cos 22/2 + sin 83 =2 sin30 x cos 11 + sin 83 = 2 x 1/2 x cos 11 + sin 83 = cos 11 + sin 83