If n=1 then sin(PI/2)=1If n=2 then sin(pi)=0If n=3 then sin(3pi/2) = sin(pi+pi/2)= -sin(pi/2)= -1If n=4 then sin(2pi)=0If n=5 then sin(5pi/2)= sin(2pi+pi/2)= sin(pi/2)= 1.Hence sin n*(pi/2)= 1 if n=1,5,9,13...= -1 if n=3,7,11,15...= 0 if n is EVEN
Your experience on this site will be improved by allowing cookies. Read Cookie Policy