# How do you use fundamental identities to find the values of the trigonometric values given tan theta = -12/5 and cos theta> 0?

Nov 11, 2016

Find values of trig functions

#### Explanation:

Consider the right triangle OAB with
OA = 5, and AB = - 12
Hypotenuse $O B = \sqrt{25 + 144 = 169} = 13$
Call t the angle < AOB:
$\cos t = \frac{5}{13} - \to \sec t = \frac{13}{5}$
$\sin t = - \frac{12}{13} - \to \csc t = - \frac{13}{12}$
t$a n t = - \frac{12}{5} - \to \cot t = - \frac{5}{12}$