limit x tends to pi/2 cotx -cosx /cos^3x Share with your friends Share 3 Rajat Sethi answered this y=limx→π2 cot x-cos xcos3xy=limx→π2 cos xsinx-cos xcos3xy=limx→π2 cosx-cos x sinxsinxcos3xy=limx→π2 1-sinxcos2x sin x∵ it is of 00 form ,using L'opitals rule,differentiating N'r and D'r,we havey=limx→π2 - cos x2cos x(-sin x)sinx+cos2x.cos xy=limx→π2 -cosx-2cosx sin2x+cos3xagain it is of 00 form ,using L'opitals rule,differentiating N'r and D'r,we havey=limx→π2 sin x-2(-sin x)sin2x-2cos x.2sinx.cosx+3cos2x(-sinx)y=limx→π2 sin x2sin3x-4cos2x.sin x-3cos2xsinxy=12(1)3-4.0.1-3.0.1y=12 -3 View Full Answer
