Determine the values of sin 2θ, cos 2θ, and tan 2θ, given tanθ = -7/24, and π/2 ≤ θ ≤ π.

Question

Determine the values of sin 2θ, cos 2θ, and tan 2θ, given tanθ = -7/24, and π/2  ≤ θ ≤ π.

goformit100 · Answer

@apoorvk

anonymous · Answer

Use them:

$$\sin2x = \frac{2tanx}{1 + \tan^2x}$$

$$\cos2x = \frac{1 -\tan^2 x}{1 + \tan^2 x}$$

anonymous · Answer

how did you come up with those ? :S
we're supposed to used double angle formulase

anonymous · Answer

Your sine value and tan value are wrong in denominator I guess @apoorvk

anonymous · Answer

$$\tan2x = \frac{2tanx}{1 - \tan^2x}$$

apoorvk · Answer

Sorry for the error!

anonymous · Answer

It is okay I am just reminding you ..

anonymous · Answer

are these double angle ?

anonymous · Answer

Yes they are..
Left hand side you have 2x and right hand side you have x..

anonymous · Answer

you have given the value of tanx, you have to just plug in that value in place of tanx in the formulas..