If cos theta = -2/3, which of the following are possible?

A. csc theta = 3/root5 and tan theta = -root5/2
B. sin theta = -root5/3 and tan theta = root5/2
C. sin theta = root5/3 and tan theta = root5/2
D. csc theta = -3/2 and tan that root 5/2

Respuesta :

Answer:

B. [tex]\sin \theta=\frac{-\sqrt{5}}{3}[/tex] and [tex]\tan \theta =\frac{\sqrt{5}}{2}[/tex]

Step-by-step explanation:

We are given that,

[tex]\cos \theta=\frac{-2}{3}[/tex].

Since, we know,

[tex]\sin^2 \theta+\cos^2 \theta=1[/tex]

i.e. [tex]\sin^2 \theta=1-\cos^2 \theta[/tex]

i.e. [tex]\sin^2 \theta=1-(\frac{-2}{3})^2[/tex]

i.e. [tex]\sin^2 \theta=1-\frac{4}{9}[/tex]

i.e. [tex]\sin^2 \theta=\frac{9-4}{9}[/tex]

i.e. [tex]\sin^2 \theta=\frac{5}{9}[/tex]

i.e. [tex]\sin \theta=\pm \frac{\sqrt{5}}{3}[/tex]

Also, we get,

[tex]\tan \theta =\frac{\sin \theta}{\cos \theta}[/tex]

i.e. [tex]\tan \theta =\frac{\pm \frac{\sqrt{5}}{3}}{\frac{-2}{3}}[/tex]

i.e. [tex]\tan \theta =\mp \frac{\sqrt{5}}{2}[/tex]

So, we get that,

Option B is correct.