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CLP-2 Integral Calculus

Section A.7 Trigonometry — Simple Identities

  • Periodicity
    sin(θ+2π)=sin(θ)cos(θ+2π)=cos(θ)
  • Reflection
    sin(θ)=sin(θ)cos(θ)=cos(θ)
  • Reflection around π/4
    sin(π2θ)=cosθcos(π2θ)=sinθ
  • Reflection around π/2
    sin(πθ)=sinθcos(πθ)=cosθ
  • Rotation by π
    sin(θ+π)=sinθcos(θ+π)=cosθ
  • Pythagoras
    sin2θ+cos2θ=1