Question 958397
Let (-4, -7) be a point on the terminal side of theta. Find the "exact values" of cos theta, sec theta, and cot theta.
***
use x for theta
reference angle x is in quadrant III, where sin<0, cos<0
hypotenuse of reference right triangle in quadrant III=&#8730;(4^2+7^2)=&#8730;(16+49)=&#8730;65
sinx=-7/&#8730;65
cosx=-4/&#8730;65=-(4&#8730;65)/65
secx=-&#8730;65/4
cotx=4/7
..
check: (w/calculator)
tanx=7/4
x&#8776;240.2551&#730;
cosx&#8776;cos(240.2551)&#8776;-0.4961
exact value=-(4&#8730;65)/65&#8776;-0.4961