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Sin 20 + sin 40 - sin 80 |
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Answer» welcome to the CONCEPT of trigonometry. formula used : sinx-siny= 2cos{(x+y)÷2 }sin {(x-y)÷2) =2cos 60 sin (-20) + sin20 =sin20[ -2cos60 +1] ( cos60=1/2) =sin20(0) =0 i hope it help you |
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