## anonymous 5 years ago Are the following true or false & why? cos(-175°) = cos(175°) cos(32°) = sin(58°) sin(π/3) = 1/sec(π/3) cos(2π/3) = cos(4π/3)

1. anonymous

first one is true because cosine is even

2. anonymous

that is to say $\cos(x)=\cos(-x)$

3. anonymous

hello anwar

4. anonymous

Hi :)

5. anonymous

second one is true because they add up to 90

6. anonymous

third one is false because the reciprocal of sine is cosecant, not secant.

7. anonymous

how am i doing so far?

8. anonymous

seems right

9. anonymous

and 4th is true

10. anonymous

really? why?

11. anonymous

CAST RULE!

12. anonymous

2pi/3 and 4pi/3 , both have relative angles of pi/3 with the x axis

13. anonymous

and cos is negative in both 2 and 3rd quadrants

14. anonymous

what the monkey is cast rule?

15. anonymous

thing its something similar to ASTC

16. anonymous

Please tell me, what is the cast rule? lol!

17. anonymous

i mean i see that they are the same from drawing a circle. so the answer is true. so i am not casting any doubts

18. anonymous

it tells you when the trig functions are positive going counterclockwise from the fourth quadrent labelling it C, then A, then S, T. C= cosine, A all, S = sine, T tan

19. anonymous

Sorry for all of the trouble I'm causing! I just really don't understand any of this :( But you guys are really helping out!!!

20. anonymous

yeh I wouldnt worry about this cast rule thing, its the first time I have ever heard of it, ever

21. anonymous

it will only confuse you

22. anonymous