Trigonometry
| sin | sin θ = cos ( θ - ½ π ) |
|---|---|
| cos | cos θ = sin ( θ + ½ π ) |
Small Angle Approximations
When θ is extremely small, for example if one cathetus is several orders of magnitude than the other, we can use the following approximations:
sin θ ≈ θ
cos θ ≈ 1 - ½ θ2tan θ ≈ θ