C chowchow New member Xu 0 7/9/12 #1 1) cho /\v ABC. góc B= α. CMR: a) Tan α = Sinα/cosα b) Costanα = cosα/sinα c)1+tan^2.α = 1/cos^2.α d) 1/costan^2.a = 1/ sin^2.α :smiley_simmons: Sửa lần cuối bởi điều hành viên: 7/9/12
1) cho /\v ABC. góc B= α. CMR: a) Tan α = Sinα/cosα b) Costanα = cosα/sinα c)1+tan^2.α = 1/cos^2.α d) 1/costan^2.a = 1/ sin^2.α :smiley_simmons: