SOLUTION: solve each equation 15) sin(2 theta) +sin( 4 theta) = 0

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Question 712339: solve each equation

15) sin(2 theta) +sin( 4 theta) = 0
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
sin(2 theta) +sin( 4 theta) = 0
sin2x +sin4x =0
sin2x+2sin2x+cos2x=0
sin2x(1+cos2x)=0
sin2x=0
2x=0
x=0
or
1+cos2x=0
cos2x=-1
2x=3π/2
x=3π/4