Question

Determine the quadrant in which theta lies:
sec theta>0 and cot theta<0
drwls
sec theta is positive where cos theta is positive. That would be the first and fourth quadrants. Cot theta is negative where tan theta is negative, and that would be in the second and fourth quadrants. The only quadrant that satifies both criteria is the fourth.
Anonymous
why is sec theta positive where cos theta is positive?
drwls
because sec theta = 1/cos theta.
Both functions have the same sign