## itsmichelle29 one year ago If sin θ = 1/4 and tan θ > 0, what is the value of cos θ?

1. misty1212

HI!!

2. misty1212

draw a triangle, like this |dw:1439233810971:dw|

3. misty1212

there is a picture of an angle where the sine is $$\frac{1}{4}$$ since the "opposite over adjacent" is $$\frac{1}{4}$$

4. misty1212

i meant "opposite over hypotenuse"

5. misty1212

what you need is the adjacent side, which you find via pythagoras let me know when you get it

6. itsmichelle29

7

7. misty1212

oh no not 7

8. misty1212

use pythagoras $a^2+b^2=c^2\\ x^2+1^2=4^2\\ x^2+1=16\\ x^2=16-1=15$ so $x=\sqrt{15}$

9. itsmichelle29

okay is the answe root15 /4

10. itsmichelle29

@misty1212

11. misty1212

yes

12. misty1212

oh no!

13. misty1212

you want the tangent right? not the cosine

14. itsmichelle29

can u help me with like two more plz

15. itsmichelle29

the cos

16. misty1212

oh ok then yes

17. misty1212

and i will be happy to help with two more

18. itsmichelle29

thanks

19. itsmichelle29

What are the period and phase shift for f(x) = −4 tan(x − π)?

20. itsmichelle29

i think its pi and pi

21. misty1212

period of tangent is $$\pi$$ so yeah

22. misty1212

phase shift is $$\pi$$ as well you are right

23. itsmichelle29

thanks and

24. itsmichelle29

Use the graph below to answer the question that follows: cosine graph with points at 0, negative 1 and pi over 2, 3 and pi, negative 1 What are the amplitude, period, and midline of the function? Amplitude: 8; period: π; midline: y = 1 Amplitude: 8; period: 2π; midline: y = 5 Amplitude: 4; period: 2π; midline: y = 5 Amplitude: 2; period: π; midline: y = 1

25. misty1212

really need the graph for this one

26. itsmichelle29

27. itsmichelle29

okay =)

28. misty1212

ok much better got a guess?

29. misty1212

only need to look at the amplitude to pick from your choices

30. itsmichelle29

Amplitude: 8; period: π; midline: y = 1 Amplitude: 8; period: 2π; midline: y = 5 Amplitude: 4; period: 2π; midline: y = 5 Amplitude: 2; period: π; midline: y = 1

31. itsmichelle29

well i thought it was -1 but thats not a chose

32. misty1212

from -1 to 3, that is from the lowest point to the highest, is a distance of 4 units the amplitude is half of that i.e. 2

33. misty1212

also you can see that the period is $$\pi$$ since it goes up, and back down to -1 from 0 to $$\pi$$

34. itsmichelle29

Amplitude: 2; period: π; midline: y = 1 is that the answer

35. misty1212

yup

36. itsmichelle29

omg ur amazing thanks

37. misty1212

lol thanks$\color\magenta\heartsuit$