C-09-Q107mediumsingle_mcqIf tanA=13\tan A = \dfrac{1}{\sqrt{3}}tanA=31, then cosec2A−sec2Acosec2A+sec2A=?\dfrac{\operatorname{cosec}^2 A - \sec^2 A}{\operatorname{cosec}^2 A + \sec^2 A} = ?cosec2A+sec2Acosec2A−sec2A=?a111b12\dfrac{1}{2}21c−12-\dfrac{1}{2}−21d000ব্যাখ্যাWith tanA=13\tan A=\tfrac{1}{\sqrt3}tanA=31, we have sec2A=1+13=43\sec^2 A=1+\tfrac13=\tfrac43sec2A=1+31=34 and cosec2A=1+cot2A=1+3=4\operatorname{cosec}^2 A=1+\cot^2 A=1+3=4cosec2A=1+cot2A=1+3=4. So the ratio is 4−434+43=8/316/3=12\dfrac{4-\tfrac43}{4+\tfrac43}=\dfrac{8/3}{16/3}=\dfrac124+344−34=16/38/3=21.