(cosecA-sinA) (secA-cosA)=1/sin^2A-sin^4A Share with your friends Share 0 Sandeep Saurav answered this To Prove : (cosec A-sin A)(sec A-cos A)=1sin2A-sin4ASolution : LHS=⇒(1sin A-sin A)(1cos A-cos A)⇒(1-sin2Asin A)(1-cos2Acos A)⇒(1-sin2Asin A)(sin2Acos A)⇒sin2A-sin4Asin A cos A⇒sin A(sin A-sin3A)sin A cos A⇒sin A-sin3A cos ARHS==1sin2A-sin4A=1sinA(sin A-sin3A)=cosec Asin A-sin3ASince LHS≠RHSSo, this identity doesnot hold. so, cannot be proved Hope this information will clear your doubts about topic. If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible. Keep posting!! Regards 0 View Full Answer