(tan x+cot x)cos平方x=

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(tan x+cot x)cos平方x=
(tan x+cot x)cos平方x=

(tan x+cot x)cos平方x=
(tan x+cot x)cos²x
=(sinx/cosx+cosx/sinx)cos²x
=(1/sinxcosx)cos²x
=cosx/sinx
=cotx

(tan x+cot x)cos^2x
=(sinx/cosx+cosx/sinx)cos^2x
=(sin^2x+cos^2x)cos^2x/(sinxcosx)
=2cos^2x/sin2x
=(1+cos2x)/sin2x

(tan x+cot x)cos平方x= (cos平方x+sin平方x)/cosxsinx*cos平方x=cot x

(sinx/cosx+cosx/sinx)(cosx)^2
=sinx*cosx+(cosx)^3/sinx
=((sinx)^2*cosx+(cosx)^3)/sinx
=(((sinx)^2+(cosx)^2)*cosx)/sinx
=cosx/sinx
=cotx