Question

упростите выражение  1-cos2a/sin2a

Answer 1

1-cos2a/sin2a=1-(cos^2x-sin^2x)/2sinxcosx=1-cos^2x+sin^2x/2sinxcosx=sin^2x+sin^2x/2sinxcosx=2sin^2x/2sinxcosx=sinx/cosx=tgx