SOLUTION: I solved all but 2 questions for my homework. The last 2 are driving me crazy. Here's the second, please help. {{{ 1.2sin(x)-9.1sin(2x)=0 }}} Hint: There are 4 answers. Can you sho

Algebra ->  Trigonometry-basics -> SOLUTION: I solved all but 2 questions for my homework. The last 2 are driving me crazy. Here's the second, please help. {{{ 1.2sin(x)-9.1sin(2x)=0 }}} Hint: There are 4 answers. Can you sho      Log On


   

Question 726806: I solved all but 2 questions for my homework. The last 2 are driving me crazy. Here's the second, please help. +1.2sin%28x%29-9.1sin%282x%29=0+ Hint: There are 4 answers. Can you show a step by step? It's the only way I can learn...
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
+1.2sin%28x%29-9.1sin%282x%29=0+
+1.2sin%28x%29-9.1%2A2sin%28x%29cos%28x%29=0+
+sin%28x%29%2A%281.2+-+18.2cos%28x%29%29=0+
sin(x) = 0
x = 0, pi
=================
1.2 - 18.2cos(x)=0
cos(x) = 1.2/18.2
x =~ 1.505
x =~ 4.778
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Those are the 4 answers between 0 and 2pi