Here's the question you clicked on:
alyssababy7
Find the exact value of the trigonometric function. cot(-5pi/4)
a. 1 b. -1 c. -sq root of 2
http://en.wikipedia.org/wiki/File:Unit_circle_angles_color.svg cot = cos/sin
cot(-5pi/4) cot(2pi - 5pi/4) cot(3pi/4) -cot(pi - 3pi/4) -cot(pi/4) -1