Question

упростите выражение 1-cos2a+sin2a/1+cos2a+sin2a

Answer 1

(1-cos2a+sin2a)/(1+cos2a+sin2a)=
=(cos²a+sin²a-cos²a+sin²a+2sinacosa)/(cos²a+sin²a-cos²a-sin²a+2sinacosa)=
=(2sin²a+2sinacosa)/(2cos²a+2sinacosa)=
=2sina/(sina+cosa)/2cosa(cosa+sina)=tga