## rudra333 Group Title arccos0? one year ago one year ago

1. tomo Group Title

1/cos(0)

2. rudra333 Group Title

$\tan ^{-1}-\frac{ \sqrt{3} }{ 3}$

3. rudra333 Group Title

@tomo is that the asnwer?

4. tomo Group Title

?? that doesn't make sense. please reword

5. rudra333 Group Title

the one with tangent?

6. rudra333 Group Title

what is arccos0??

7. tomo Group Title

cos(0) = 1.

8. rudra333 Group Title

@tomo

9. Inspired Group Title

arccos(0)= 90 degrees or pi/2

10. tomo Group Title

one second. it is a little different than i first thought it was.

11. rudra333 Group Title

k but plz try to expalin i have test on this toorrow

12. rudra333 Group Title

k what is the answer of the questio with tangent?

13. rudra333 Group Title

@Inspired

14. Inspired Group Title

Well it's just the inverse of cos(0). Cos(0) =1. The inverse of that switches the values of the sine cosine functions. cos(90) gives you 1. but because remember, sin(0)=0 and sin(90)=1

15. Inspired Group Title

cos(90) is 0*

16. Inspired Group Title

and an easy way to remember is: sin is your y axis and cos is your x axis. the inverse of a function is basically switches the x and y. what was y=f(x) is now x=f(y)

17. rudra333 Group Title

k i know that but i have like 5 problems to work on i just want the right answers to it so i can practice

18. rudra333 Group Title

for the test tomorrow

19. rudra333 Group Title

socan u tell me the answer to the tangent one?plz

20. rudra333 Group Title

$\arcsin-\frac{ \sqrt{3} }{ 2 }$

21. rudra333 Group Title

and this one plz i have to go emergency plz answe those 2 for me plz

22. rudra333 Group Title

23. Inspired Group Title

-pi/6 and -pi/3 (take a look at the unit circle for the second one)

24. fgoh Group Title

how did u get -pi/6? i know in the unit cirlce but when i tried all of them tan is y/x then which onw will work?

25. fgoh Group Title

@Inspired

26. Inspired Group Title

Let's see. arctan (sqrt3/3) is the same thing as arctan (1/sqrt3) right? and using 30-60-90 triangle, you have this: |dw:1358819026253:dw|

27. Inspired Group Title

Anyway, since the value is negative, it will occur in the 2nd or 4th Quadrant. Since we want a single value, you usually use the 4th quadrant, and that gives you a negative value.

28. fgoh Group Title

but is is y/x right why it doesn't work

29. fgoh Group Title

if u do it with the values on unit square and i thought the domain is from (pi/2,-pi/2)?

30. fgoh Group Title

|dw:1358819636475:dw|

31. fgoh Group Title

OMG K GET IT THANKS THANKS ALOT @Inspired U ARE AWESOME AND HELPFUL OMG THANKS THANKS I JUST FEEL SO HAPPY WHEN I GET IT THANKS

32. Inspired Group Title

:)

33. fgoh Group Title

$COS ^{-1}(\sin 11\pi/6)$

34. fgoh Group Title

@Inspired

35. fgoh Group Title

@Inspired last one

36. fgoh Group Title

and which one do u do first?

37. Inspired Group Title

ok :0 sin(11pi/6) is the same thing as sin(12pi/6-pi/6) so you get sin(2pi-pi/6) --> -sin(pi6)=-1/2 and so you have arccos(-1/2)

38. rudra333 Group Title