[Math] Solve the equation $(tan θ − 2)(9 sin^2 θ − 1) = 0$

trigonometry

Solve the given equation. (Enter your answers as a comma-separated list. Let $k$ be any integer. Round terms to three decimal places where appropriate. If there is no solution, enter NO SOLUTION.)

$$(\tan \theta − 2)(9 \sin^2 \theta − 1) = 0$$

So if I set both equal to zero and solve I get

$$\theta=\tan^{-1}(2)$$

$$\theta=\sin^{-1}\left(\frac13\right)$$

$$\theta=\sin^{-1}\left(-\frac13\right)$$

What do I do next?

Update:

There should be five answers, so far I have 4:

$1.107+\pi k$ which came from the tangent

$0.340+2\pi k$ which came from arcsin (1/3)

$2.802+2\pi k$ which came from arcsin (1/3)

$5.943+2\pi k$ which came from arcsin (-1/3)

There should be one more from came from arcsin (-1/3) but I don't know what to add/subtract from arcsin (-1/3) to get it.

Edit: I got the last one it was $3.481+2\pi k$

Best Answer

A Couple things:

You should get 3 results: $ (\tanθ−2)(9\sin2θ−1)=0 \Rightarrow$

$ (1) \tanθ =2$

$ (2) \sinθ = \frac{1}{3}$

$ (3) \sinθ = -\frac{1}{3} $

From here, you would use the inverse functions as you did- however, it seems as if you may use a calculator to get your results, which would probably be your best bet (assuming you are given a fixed domain)