Question 802950
What is the sin and cos for 26(pie)/3 , 17(pie)/4 , and 34(pie)/3?
***
26π/3=24(π/3)+2(π/3)=8π+2π/3
This is like rotating counter clockwise 8&#960; around a unit circle plus an additional 2&#960;/3 which places the reference angle of 2&#960;/3 in quadrant II where sin>0 and cos<0. 
sin(26&#960;/3)=sin(2&#960;/3)=&#8730;3/2
cos(26&#960;/3)=cos(2&#960;/3)=-1/2
..
17&#960;/4=16(&#960;/4)+(&#960;/4)=4&#960;+&#960;/4
This is like rotating counter clockwise 4&#960; around a unit circle plus an additional &#960;/4 which places the reference angle of &#960;/4 in quadrant I where sin>0 and cos>0. 
sin(17&#960;/4)=sin(&#960;/4)=&#8730;2/2
cos(17&#960;/4)=cos(&#960;/4)=&#8730;2/2
..
34&#960;/3=33&#960;/3)+(&#960;/3)=11&#960;+&#960;/3
This is like rotating counter clockwise 11&#960; around a unit circle plus an additional &#960;/3 which places the reference angle of &#960;/3 in quadrant III where sin<0 and cos<0. 
sin(34&#960;/3)=sin(&#960;/3)=-&#8730;3/2
cos(34&#960;/3)=cos(&#960;/3)=-1/2