Question

Find the value of tan theta if sin theta = 12/13 and theta is in quadrant 2

Answer 1

Answer:

tanΘ = - $\frac{12}{5}$

Step-by-step explanation:

Using the trigonometric identities

• sin²x + cos²x = 1, hence

cosx = ± √(1 - sin²x )

• tanx = $\frac{sinx}{cosx}$

given sinΘ = $\frac{12}{13}$, then

cosΘ = ±  $\sqrt{1-(12/13)^2}$

Since Θ is in the second quadrant where cosΘ < 0, then

cosΘ = - $\sqrt{1-\frac{144}{169} }$

         = - $\sqrt{\frac{25}{169} }$ = - $\frac{5}{13}$

tanΘ = $\frac{\frac{12}{13} }{\frac{-5}{13} }$

        = $\frac{12}{13}$ × - $\frac{13}{5}$ = - $\frac{12}{5}$