A complex number is said to be purely imaginary if it has no real part, i.e., . The term is often used in preference to the simpler "imaginary" in situations where can in general assume complex values with nonzero real parts, but in a particular case of interest, the real part is identically zero.

# Purely Imaginary Number

## See also

Complex Number, Complex Plane, Imaginary Number, Real Part## Explore with Wolfram|Alpha

## Cite this as:

Weisstein, Eric W. "Purely Imaginary Number."
From *MathWorld*--A Wolfram Web Resource. https://mathworld.wolfram.com/PurelyImaginaryNumber.html