Let 0<a<π20<a<\dfrac{\pi}{2}0<a<2π satisfy cos2a−cos(2a)=sin(2a).\cos^2a-\cos(2a)=\sin(2a).cos2a−cos(2a)=sin(2a). Which of the following is true for this value of aaa? Atana=15\tan a=\dfrac{1}{5}tana=51Bcota=25\cot a=\dfrac{2}{\sqrt{5}}cota=52Ccosa=15\cos a=\dfrac{1}{\sqrt{5}}cosa=51Dcoseca=5\operatorname{cosec}a=\sqrt{5}coseca=5Esin(2a)=35\sin(2a)=\dfrac{3}{5}sin(2a)=53