## anonymous one year ago If sin θ = 1/3 and tan θ < 0, what is the value of cos θ?

1. anonymous

draw a triangle

2. anonymous

|dw:1442452830325:dw|

3. anonymous

there is a picture of an angle whose sine is $$\frac{1}{3}$$ find the missing side via pythagoras

4. anonymous

you can pretty much do it in your head what is $$3^2$$?

5. anonymous

9

6. anonymous

and $$1^2$$?

7. anonymous

1

8. anonymous

and $$9-1$$?

9. anonymous

8

10. anonymous

so answer for the missing side is $$\sqrt{8}$$ now two more steps

11. anonymous

2√2

12. anonymous

|dw:1442453007407:dw|

13. anonymous

yeah that too now the cosine is adjacent over hypotenuse, but don't forget that $$\tan(\theta)<0$$ which means the cosine must be negative

14. anonymous

-√8/3

15. anonymous

or -(2√2)/3

16. anonymous

yes probably your teacher will like the second one more

17. anonymous

YES! thank you! you're gr8 :)

18. anonymous

lol yw