Solve each equation from 0-180 degrees

[Guest]

Yes it's Carlos again. I have to turn my homework in next period and I need help understanding what I have to do in oreder to solve some of my equations.

I can solve this one: 2cos x -1 = 0 (It = 60 degrees right?)

But I can not solve the following:

sin x = tan x

sin x * tan x - tan x = 0

2sin^2 x - 5sin x +2= 0

And a few more but I think I just need to be taught how to do them and you don't have to solve all of them I just need to learn how. (I have to leave in 10 min. to this class)

 

[stapel]

1) Solve 2cos(x) - 1 = 0 on the interval 0° < x < 180°.

Your solution is correct.

2) Solve sin(x) = tan(x) on the interval 0° < x < 180°.

One method would be to rewrite this in terms of sines and cosines, and then consider two cases. Either sin(x) = 0 (which means what?) or else it doesn't (which means you can divide through by "sin(x)" to get what?).

3) Solve [sin(x)][tan(x)] - tan(x) = 0 on the interval 0° < x < 180°.

Factor out the tangent, and then solve the factors.

4) Solve 2sin²(x) - 5sin(x) + 2 = 0 on the interval 0° < x < 180°.

If they'd given you "2y² - 5y + 2 = 0", what would you have done? Follow the same general procedure, and then solve the resulting trig equations for x.

If you get stuck, please reply showing what you have tried and how far you have gotten. Thank you.

Eliz.