Question #b4d8f
1 Answer
May 31, 2017
Explanation:
#2costheta+1=0#
#rArrcostheta=-1/2#
#"since the ratio is negative " theta" will be in the"#
#"second and third quadrants"#
#rArrtheta=cos^-1(1/2)=pi/3larrcolor(red)" related acute angle"#
#rArrtheta=(pi-pi/3)=(2pi)/3larrcolor(blue)" second quadrant"#
#rArrtheta=(pi+pi/3)=(4pi)/3larrcolor(blue)" third quadrant"#
#rArrtheta=(2pi)/3,(4pi)/3to[0,2pi)#
