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## anonymous one year ago Solve the equation in the specified interval Secx=-3 -pi</x<pi

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1. misty1212

HI!!

2. misty1212

start with $\cos(x)=-\frac{1}{3}$

3. misty1212

then comes some difficulty

4. anonymous

Hey! Yes I started with that

5. misty1212

so now you are stuck since you don't know the answer to that

6. anonymous

Basically I'm stuck in this step

7. misty1212

you need to use a calculator to find $\cos^{-1}(-\frac{1}{3})$

8. misty1212

that will only give you one answer in quadrant 2 though

9. anonymous

Ok I got it

10. misty1212

|dw:1440123708272:dw|

11. misty1212

you want the other one, it is the negative of the first one

12. misty1212

|dw:1440123787810:dw|

13. anonymous

So first one is 1.91

14. misty1212

hmm let me check

15. misty1212

http://www.wolframalpha.com/input/?i=arccos%28-1%2F3%29 yeah looks good

16. anonymous

Ok so how do I get the opposite

17. misty1212

it is the negative of the first one

18. anonymous

-1.91?

19. misty1212

|dw:1440124243706:dw|

20. misty1212

scuse the bad picture yeah what you wrote

21. anonymous

Ok so how would you write to make it look like pi/2

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