C-09-Q091mediumsingle_mcqIf tanA+sinA=a\tan A + \sin A = atanA+sinA=a and tanA−sinA=b\tan A - \sin A = btanA−sinA=b, then a2−b2=?a^2 - b^2 = ?a2−b2=?a4ab4ab4abb4ab4\sqrt{ab}4abc2ab2ab2abd2ab2\sqrt{ab}2abব্যাখ্যাNote a2−b2=(a+b)(a−b)=(2tanA)(2sinA)=4tanAsinAa^2 - b^2 = (a+b)(a-b) = (2\tan A)(2\sin A) = 4\tan A\sin Aa2−b2=(a+b)(a−b)=(2tanA)(2sinA)=4tanAsinA. Also ab=(tanA+sinA)(tanA−sinA)=tan2A−sin2A=tan2Asin2Aab = (\tan A+\sin A)(\tan A-\sin A) = \tan^2 A - \sin^2 A = \tan^2 A\sin^2 Aab=(tanA+sinA)(tanA−sinA)=tan2A−sin2A=tan2Asin2A, so 4ab=4tanAsinA=a2−b24\sqrt{ab} = 4\tan A\sin A = a^2-b^24ab=4tanAsinA=a2−b2.