| InvalidOperationException | x is signaling NaN or ±∞ |
| UnderflowException | result is too small to be represented |
| InexactException | the result is inexact |
| x | cos(x) |
|---|---|
| NaN | NaN |
| ±∞ | NaN |
| ±0.0 | +1.0 |
| π/6 | +√3/2 |
| π/4 | +√2/2 |
| π/3 | +0.5 |
| π/2 | +0.0 |
| 2π/3 | -0.5 |
| 3π/4 | -√2/2 |
| 5π/6 | -√3/2 |
| π | -1.0 |
Returns cosine of x.