Question 650303
csc (2pi/3) and (sec450º)
Each circle contains 360º or 2π radians divided into 4 quadrants.
All you need to do is determine which quadrant the angle is in from which you can determine its sign as follows:
quadrant I:
all functions>0
..
quadrant II
sin and csc >0
cos and sec<0
tan and cot<0
..
quadrant III
sin and csc <0
cos and sec<0
tan and cot>0
..
quadrant IV
sin and csc <0
cos and sec>0
tan and cot<0
..
csc (2pi/3) is in quadrant II, therefore, its sign>0
sec450ºis going around the circle once and ending at 90º or &#960;/2
sec 450º=1/cos450º=1/cos90º=1/0=undefined
hope this helps