## Equation Solving: solve 2 sin x + 1 = 0 for x, 0 <= x < 2pi

Trigonometric ratios and functions, the unit circle, inverse trig functions, identities, trig graphs, etc.
hakandragon
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Joined: Mon May 04, 2009 10:08 pm
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### Equation Solving: solve 2 sin x + 1 = 0 for x, 0 <= x < 2pi

If someone could point me in the right direction of where to go with these sorts of problems, I would be so greatful :p

Solve the equation for x, where 0</x<2pi

2 sin x + 1 = 0

stapel_eliz
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Joined: Mon Dec 08, 2008 4:22 pm
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How would you solve 2x + 1 = 0? Start the solution in the same manner.

For what value of x is sin(x) equal to -1/2? Complete the solution using this information.

hakandragon
Posts: 13
Joined: Mon May 04, 2009 10:08 pm
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### Re: Equation Solving: solve 2 sin x + 1 = 0 for x, 0 <= x < 2pi

I'm sorry, I know this is probably a problem I should be able to do in my head or something, but I'm still confused :(

stapel_eliz
Posts: 1628
Joined: Mon Dec 08, 2008 4:22 pm
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Okay, so first you'll need to re-learn how to solve linear equations. Once you've got that down, you can solve for "sin(x)=".

Then you'll need to re-learn the basic reference-angle values for the trig functions. Once you've got that down, you can find at least one solution to the trig equation. To find the other solution, you'll need to review the sine values for one period.