## aussy123 2 years ago I have a question, can someone answer me. Metal awarded.

1. aussy123

I have a problem and it ask for tan2theta, and theta is in the 1st quad, but when I work out the problem I get a negative result. Do that number automatically turns positive?

2. aussy123

does*

3. aussy123

do you know anything about tan, sin and cos?

4. completeidiot

$\tan^2 \theta$ $0^\circ<\theta<90^\circ$ whats the question?

5. completeidiot

or is it $\tan (2\theta)$?

6. aussy123

$\tan2\Theta$

7. completeidiot

what is the original question?

8. aussy123

Given: sin =4/5 and cos x =-5/13 ; evaluate the following expression. (Theta: Quadrant I, x : Quadrant II.) tan 2 Theta a.) 8/3 b.) 24/7 c.) -24/7

9. aussy123

my outcome is -24/7 but theta is in the first quad and tan is positive in the first quad

10. Mertsj

If theta is greater than 45 and in the first quadrant, then 2 theta is in the second quadrant where the tangent is negative.

11. completeidiot

yes theta is in the first quadrant, but you're not finding tan(theta) you're finding tan(2*theta) and its possible for 2*theta to be in the second quadrant as mertsj just stated

12. aussy123

So my result stays at -24/5

13. aussy123

14. completeidiot

assuming you didnt make any mistakes in your calculation, then that would be the answer note- i didnt actually do the problem

15. aussy123

okay Thank You both, now I can start my quiz with no problem. fingers crossed!