d/dx (x+cosx ÷ tanx ) = d/dx (x+cosx/tanx ) ddx(x+cosx÷tanx)=ddx(x+cosxtanx)
" "= d/dx (x)+d/dx(cosx/tanx) =ddx(x)+ddx(cosxtanx)
" "= 1 + { (tanx)(-sinx) - (cosx)(sec^2x) }/ (tanx)^2 =1+(tanx)(−sinx)−(cosx)(sec2x)(tanx)2
" "= 1 - (tanx)(sinx)/tan^2x - (cosx)(sec^2x)/(tanx)^2 =1−(tanx)sinxtan2x−(cosx)sec2x(tanx)2
" "= 1 - (sinx)*cosx/sinx - (cosx)(1/cos^2x)*cos^2x/sin^2x =1−(sinx)⋅cosxsinx−(cosx)(1cos2x)⋅cos2xsin2x
" "= 1 - cosx - (cosx)/sin^2x =1−cosx−cosxsin2x
" "= 1 - cosx - cotxcscx =1−cosx−cotxcscx