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

1. anonymous

A) negative square root of 15 B) square root of 15 C) square root of 15 over 4 D) negative square root of 15 over 4

2. anonymous

I will give you a hint: $\theta is \in the first quadrant. That means \between 0 and 90 degree.$

3. anonymous

and im lost

4. anonymous

hhhha

5. anonymous

Okey you know: $\cos^2\theta+\sin^2\theta=1$

6. anonymous

sure

7. anonymous

$\cos^2\theta+(\frac{ 1 }{ 4 })^2=1$

8. anonymous

Do you know how to solve the previus eauation!

9. anonymous

nope

10. anonymous

look i appreciate ur helping me but i just want the answer plz

11. anonymous

You have to learn :)

12. anonymous

$\cos \theta=\sqrt{1-\frac{ 1 }{ 16 }}$

13. anonymous

insert it in the calc!

14. anonymous

ok

15. anonymous

0.96?

16. anonymous

$\frac{ \sqrt{15} }{ 4 }$

17. anonymous

i should learn to read it says the SINE

18. anonymous

|dw:1438368638170:dw|

19. anonymous

adjacent sides is $$\sqrt{4^2-1^2}=\sqrt{15}$$

20. anonymous

oh

21. anonymous

so the cosine is $$\frac{\sqrt{15}}{4}$$ same answer as the other way, just a different perspective