## Kazwaz one year ago If tan x =3/5 and x is greater than 180 degrees but smaller than 270 degrees. What is the exact value of sin x and cos x ?

1. Mertsj

That means the angle is in Quadrant III

2. Mertsj

|dw:1393719640331:dw|

3. Mertsj

Find the hypotenuse then use the definitions of sin and cos. (Remember: sin and cos are both negative in Quadrant III)

4. Kazwaz

Sorry, can you go a bit further. Trying to help my daughter .

5. Mertsj

Would I be correct in assuming that you know the Pythagorean Theorem?

6. Kazwaz

Yes

7. Mertsj

Use it to find the hypotenuse in that right triangle.

8. Kazwaz

5.83

9. Mertsj

I believe your problem specifies "exact form"

10. Kazwaz

So I leave it as sq root 34. Then cos x is -5/sq root 34 and sin x is -3/sq root 34. Is that correct?

11. Mertsj

|dw:1393720948851:dw|

12. Kazwaz

Sorry, why are you multiplying by sq rt 34, then dividing by 34 ?

13. Mertsj

It is not considered simple form to have a radical in the denominator.

14. Mertsj

$\frac{5}{\sqrt{34}}\times \frac{\sqrt{34}}{\sqrt{34}}=\frac{5\sqrt{34}}{34}$

15. Kazwaz

Thanks for that. You've Ben a great help.

16. Kazwaz

been

17. Mertsj

yw