Q3 of 90 Page 8

Prove that :

sin 50° – sin 70° + sin 10° = 0

Take LHS:


sin 50° – sin 70° + sin 10°





= 2 cos 60° sin (-10°) + sin 10°


{sin (-A) = -sin (A)}



= - sin 10° + sin 10°


= 0


= R.H.S


Hence Proved


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