삼각함수 공식.
sin(-θ)=-sinθ, cos(-θ)=cosθ, tan(-θ)=-tanθ sin²θ+cos²θ=1, sec²θ-tan²θ=1, csc²θ-cot²θ=1 sin(π/2-θ)=cosθ, sin(π/2+θ)=cosθ, sin(θ±π/2)=±cosθ cos(π/2-θ)=sinθ, cos(π/2+θ)=-sinθ, cos(θ±π/2)=Ŧsinθ sin(π-θ)=sinθ, sin(π+θ)=-sinθ, sin(θ±π)=-sinθ cos(π-θ)=-cosθ, cos(π+θ)=-cosθ, cos(θ±π)=-cosθ sin(α±β)=sinαcosβ±cosαsinβ, cos(α±β)=cosαcosβŦsinαsinβ tan(α+β)=tanα+tanβ/1-tanαtanβ, tan(α-β)=tanα-tanβ/1+tanαtanβ..
2009. 9. 15.