## StudyGurl14 one year ago Help with trignometric equations! MEDAL

1. StudyGurl14

|dw:1441828891570:dw| How do I eliminate one of the functions so I can solve for x?

2. campbell_st

start by making the subsitution sin^2 = 1 - cos^2

3. Nnesha

sin^2 x+ cos^2 = 1 solve for sin^2 x then replace sin^2x with that

4. campbell_st

then rewrite the equation with all terms on one side and then you'll be solving a quadratic equation

5. StudyGurl14

Okay, thanks. I'll try that.

6. StudyGurl14

I'm stuck @Nnesha @campbell_st |dw:1441829434455:dw|

7. Nnesha

i guess typo a(b+c)=ab+ac

8. campbell_st

|dw:1441829240020:dw|

9. Nnesha

|dw:1441829549441:dw|

10. StudyGurl14

still stuck |dw:1441829563686:dw|

11. campbell_st

then is $2\cos^2(x) + \cos(x) = 0$ factor this

12. StudyGurl14

Oh, okay. I get the rest. Thanks!

13. StudyGurl14

|dw:1441829644394:dw|

14. campbell_st

and don't forget the other solution

15. campbell_st

|dw:1441829404062:dw|

16. StudyGurl14

|dw:1441829749290:dw|

17. StudyGurl14

like that?

18. campbell_st

that's correct... so you now just need the angles...

19. StudyGurl14

thanks! I got it from here.