A real part is the first element of the ordered pair of real numbers representing a complex number, i.e. if <math>z = x+iy<math>, then the real part is <math>x<math> and notated <math>\mbox{Re}z<math> or <math>\Re z<math>.

In terms of the complex conjugate it is <math>z+\bar z\over2<math>. It is not holomorphic.

The real part of the complex number returned by a complex function.

If a complex number is of the form <math>re^{i\theta}<math>, then the real part is <math>r\cos(\theta)<math>.

See also

• Imaginary part
• Complex number