SOLUTION: solve for x-values between [0,2pi) 6sin^2x+9sinx+3=0

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Question 822038: solve for x-values between [0,2pi)
6sin^2x+9sinx+3=0

Found 2 solutions by KMST, lwsshak3:
Answer by KMST(5328)   (Show Source): You can put this solution on YOUR website!



Either
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or
--> .

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because -->-->--> and
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TIP:
When you get a problem like, you can change variable, or at least think of it that way.
In this case, if you substitute the equation transforms into the simple quadratic equation
.
It is a lot easier to write, and a lot easier to see how to factor it and solve it.

Answer by lwsshak3(11628)   (Show Source): You can put this solution on YOUR website!
solve for x-values between [0,2pi)
6sin^2x+9sinx+3=0
divide by 3
2sin^2x+3sinx+1=0
factor:
(2sinx+1)(sinx+1)=0
..
2sinx+1=0
sinx=-1/2
x=5π/4,7π/4 (in quadrant III and IV in which sin>0)
or
sinx+1=0
sinx=-1
x=3π/2

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