SOLUTION: Show an evaluation of sin 120 degrees using the trigonometric addition formulas. Show an evaluation of sin 120 degrees using the double-angle formulas.

Question 431148: Show an evaluation of sin 120 degrees using the trigonometric addition formulas.
Show an evaluation of sin 120 degrees using the double-angle formulas.
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
Show an evaluation of sin 120 degrees using the trigonometric addition formulas.
Show an evaluation of sin 120 degrees using the double-angle formulas...
..
Addition formula:
sin(x+y)=sinxcosy+cosxsiny
sin120=sin(60+60)
=sin60cos60+cos60sin60
=(sqrt(3)/2)(1/2+(1/2)(sqrt(3)/2)
=(sqrt(3)/2)
..
Double angle formula:
Sin2x=2sinxcosx
Sin120=2sin60cos60
=2(sqrt3/2)(1/2)
=(sqrt3/2)

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