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#1

$Old$ November 14th, 2009, 08:56 PM

samtheman17 $samtheman17 is offline$

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$Default$ solving for x

Solve the following for x:

2cos(x)+sin(2x)= 0, 0 (less than or equal to) x (less than) 2%pi

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#2

$Old$ November 14th, 2009, 09:09 PM

mathaddict $mathaddict is offline$

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Solve the following for x:

2cos(x)+sin(2x)= 0, 0 (less than or equal to) x (less than) 2%pi

hi

$2\cos x+2\sin x\cos x=0$

$2\cos x(1+\sin x)=0$

Solve

$2\cos x=0$ and $1+\sin x=0$

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#3

$Old$ November 14th, 2009, 09:28 PM

samtheman17 $samtheman17 is offline$

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okay so then cosx= 0 and sinx = -1

so the solution set would look like, %pi/2 , 3*%pi/2

thank you for your help!

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#4

$Old$ November 14th, 2009, 09:32 PM

mathaddict $mathaddict is offline$

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Originally Posted by samtheman17 $View Post$

okay so then cosx= 0 and sinx = -1

so the solution set would look like, %pi/2 , 3*%pi/2

thank you for your help!

yeah , it should be clear if you draw the sin and cosine graphs and take solutions between 0 and 2pi.

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