tana=2,则2sin^a-3sina*cosa=

已知tana=3,求①sina+cosa/2sina-cosa ②sin²a+sina·cosa+3cos&# （2sin^2a+sin2a)/(1+tana) 整理 =[2sina(sina+cosa)]/[(sina+cosa) tana=2,求2sina+cosa/sina-cosa和sin^2a-2Sinacosa+3cos^2a 已知tana/tana-1=-1,求下列各式的值（1）sina-3cosa/sina+cosa(2)sin^2a+sin 求证sin^2a*tana+cos^2a*1/tana+2sina*cosa=tana+1/tana tanA=1/ tanA=sinA/ cotA=cosA/ sin^2A+cos^2A= 已知tana=2,则sin^2a+sina*cosa-2cos^2a= 已知tana=3,求下列各式的值 1.sina+cosa/sina-cosa 2.sina.cosa 3.sin^2 a tana=2 5-2sinacosa=?(sina+cos^3a)/cosa+sin^3a=? 已知tana=3 求2sin(a)^2 +sina*cosa-3cos(a)^2值 已知tana=3,求sin^2a+sina*cosa+3cos^2a 已知tana=2,则sin²a+2sina*cosa=