SOLUTION: find all the values of x in the interval [0,2pi] for 14 cos(x) + 7 sin(2x)=0

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Question 794900: find all the values of x in the interval [0,2pi] for
14 cos(x) + 7 sin(2x)=0

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
find all the values of x in the interval [0,2pi] for
14 cos(x) + 7 sin(2x)=0
7(2cos(x)+sin(2x)=0
(2cos(x)+2sin(x)cos(x)=0
cos(x)+sin(x)cos(x)=0
cos(x)(1+sin(x))=0
cos(x)=0
x=π/2, 3π/2
1+sin(x)=0
sin(x)=-1
x=π
...
x=π/2, π, 3π/2