### 7.3.8 Sine integral function

The sine integral function is defined by

Si(x)= | ∫ |
x
0
sin(t)
t
| d t.

It can be shown that Si(0)=0, Si(−∞)=−π/2 and Si(+∞)=π/2. Note that Si is an odd function.

The Si command computes the sine integral function.

- Si command takes z, a complex number.
- Si(z) returns the value of the sine integral function Si(z).

#### Example

Si(1.0)

0.946083070367 |  |  |  |  |  |  |  |  |  |

Si(-1.0)

−0.946083070367 |  |  |  |  |  |  |  |  |  |