Download Reference Angles

Pre calculus Problem of the Day
Homework: p. 499 1-33 odds
Given:
Find:


sin  
3
8
and theta is in quadrant I
cos  
55
8
tan  
3 55
55



Trigonometric functions for any angle in standard position.
If P(x, y) is a point on the terminal side of

and r is the distance from the origin to P( x, y) then:
r  x 2  y2


y
x
sin  
cos 
r
r

r
r
csc  
sec  
y
x
y
tan  
x
x
cot  
y
Pre calculus Problem of the Day
Homework: p. 499 35-85 odds, 87, 97, 99, 101
Find the value of the six trigonometric functions given the
point ( 5, -2 ) is located on the terminal side of the angle  .
2 29
29
sin   
csc   
29
2
cos  
tan  
5 29 sec  
29
2 cot  

5
29
5
5

2

Reference Angle  ' is associated with the angle,  .
 Is an angle in standard position.


 ' is the acute angle formed with the terminal side of 
and the x-axis.
If 
Is positive and between 0 and 360 or
 0 and 2  ,
then for theta in quadrant I

' 
'

 180   or   
then for theta in quadrant
 II
'
then for theta in quadrant III    180 or   

'
then for theta in quadrant
IV

 360   or 2  

