With a negative fraction, which number is negative, the denominator or the numerator? (For determining the quadrant of an angle from a trig value.)

Question

I'm in Pre-Calculus and were doing trigonometry and their functions, so I have to figure out which number on the fraction is negative.

For example: $\cos x=-(5/8)$ on the 2nd quadrant and I have to find $\tan x$ and $\csc x$. $\csc x$ is easy, because all I have to do is flip the numbers and I don't have to worry which number is negative. But with $\tan x$, I do need to know.

Thanks!