Тригонометрия


  1. sin x=a/c
  2. cos x =b/c
  3. tg x =a/b=sin/cos x
  4. ctg x =b/a =cos x/sin x
  5. sin(π* -α)=sin α
  6. sin(π*/2-α)=cos α
  7. cos(π*/2-α)=sin α
  8. cos(α+2π*k)=sin α
  9. sin(α+2π*k)=cos α
  10. tg(α+2π*k)=tg
  11. ctg(α+2π*k)=ctg
  12. sin2 α+cos2 α=1
  13. ctg a=cos α/sin α, α≠π*n, n∈Z
  14. tg α*ctg α=1, α ≠(π*n)/2, n∈Z
  15. 1+tg α =1/cos2α, α ≠π*(2n+1)/2
  16. 1+ctg α =1/sin2α, α ≠π*n


*π ≈ 3,1415926535