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Imaginary unit

`1i`

`z = a + bi`

```
z = x +
1i*y
```

`1i`

returns the basic imaginary unit. `i`

is
equivalent to `sqrt(-1)`

.

You can use `i`

to enter complex numbers.
You also can use the character `j`

as the imaginary
unit. To create a complex number without using `i`

and `j`

,
use the `complex`

function.

For speed and improved robustness in complex arithmetic, use

`1i`

and`1j`

instead of`i`

and`j`

.Since

`i`

is a function, it can be overridden and used as a variable. However, it is best to avoid using`i`

and`j`

for variable names if you intend to use them in complex arithmetic.Use the

`complex`

function to create a complex output in the following cases:When the names

`i`

and`j`

might be used for other variables (and do not equal`sqrt(-1)`

)When the inputs are not

`double`

or`single`

When the imaginary component is all zeros

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