## anonymous one year ago Verify the identity. cotx minus pi divided by two. = -tan x

1. anonymous

Is the identity pi/2?

2. David27

@iloveyou;*

3. anonymous

i suck at math sorry :/

4. anonymous

@Haseeb96

5. Haseeb96

sorry i also dont know

6. Haseeb96

@Nnesha

7. anonymous

I want to believe the identity is pi/2.

8. David27

@dan815

9. David27

@ganeshie8

10. Nnesha

verify. you need to prove that both sides are equal

11. Haseeb96

yes

12. Haseeb96

i have sucked that how to do verify it @Nnesha

13. Nnesha

remember tan =sin /cos so you can write tan in terms of sin/cos

14. dan815

hello

15. dan815

remember complimentary angles for sin and cos

16. dan815

|dw:1438277241493:dw|

17. Nnesha

$\large \rm cot (x - \frac{ \pi }{ 2 }) =\frac{ \cos( \frac{ \pi }{ 2 }- x) }{ \sin(\frac{ \pi }{ 2 } -x)}$ i guess we have to use this formulas http://prntscr.com/7ywjsc :D and btw i meant to say write cot in terms of cos/sin

18. anonymous

What do we do from here?

19. dan815

ok well lets fix these errors first

20. Nnesha

use these two formulas http://prntscr.com/7ywn75

21. dan815

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22. dan815

|dw:1438277660458:dw|

23. Nnesha

opps the negative sign ~.~

24. dan815

|dw:1438277743950:dw|

25. dan815

see why cos(90 deg - x) = sin(x)

26. dan815

you have a lot of information here, look through this stuff and work out your problem now

27. Nnesha

and u should remember even/odd formulas $\cos( - x) = \cos(x)$$\sin(-x)=-\sin(x)$$\tan(-x)=-\tan(x)$