# mathematics

posted by .

given tanθ= -2√10/3 and π/2<θ< π find:

a.sin2θ

b.tan θ/2

could some1 help me with these 2 they're the only ones i couldn't get

• mathematics -

OK so it is in the second quadrant and the reference angle is arctan 2√10/3.
The ref. angle is arctan2.1082 = 64.6 degrees.
The angle itself is 180 -64.6 = 115.4 degrees = 2.0137 radians.

use that to compute (a) and (b)

## Respond to this Question

 First Name School Subject Your Answer

## Similar Questions

1. ### Math - Calculus

The identity below is significant because it relates 3 different kinds of products: a cross product and a dot product of 2 vectors on the left side, and the product of 2 real numbers on the right side. Prove the identity below. | a …
2. ### trig

cosθ =5/13 with -π/2 < θ <0 find each of the following sin( θ - 5π/4) cos( θ - 11π/6) tan( θ + 5π/4) can some1 explain to me how to do these?
3. ### trigonometry

tanθ= -2sqrt10/3 and π/2<θ< π find a. cos(-θ) b. cos(11π/6 - θ) c.sin2θ d.tanθ/2 can some please explain to me how to solve these questions?
4. ### math

given sinθ=-5/13 and π<θ<3π/2 find sin2θ cos( θ-4π/3) sin(θ/2) can some1 explain to me how to do these?
5. ### math

if cosθ=2/3 and tanθ<0 find the exact value sin(θ-5π/3) sin2θ cos2θ cos(θ/2) can some1 please help me?
6. ### trigonometry

given tanθ= -2√10/3 and π/2<θ< π find: sin2θ tan θ/2 given sinθ=-5/13 and π<θ<3π/2 find sin2θ cos( θ-4π/3) sin(θ/2) can some1 explain this to me …
7. ### trigonometry

if cosθ=2/3 and tanθ<0 find the exact value sin(θ-5π/3) sin2θ cos2θ cos(θ/2) can some1 please help me?
8. ### mathematics

given sinθ=-5/13 and π<θ<3π/2 find sin2θ cos( θ-4π/3) sin(θ/2) can some1 please help me with this?
9. ### Pre-Calculus

If θ represents an angle such that sin2θ = tanθ - cos2θ, then sin θ - cosθ = A. -√2 B. 0 C. 1 D. 2√2 What equation can I use to solve this problem?
10. ### Precalc/Trig

Sorry there are quite a few problems, but I just need to know if these are correct (and if they aren't, where I went wrong): 1. Solve these equations. tanθ = -√3 θ = 2π/3 + kπ θ = 5π/3 + kπ …

More Similar Questions