# Converting Complex Numbers

## Polar to Rectangular Forms Using Calculator

## Choosing a Calculator

The first example is applicable to most advanced calculators, while the second example is specific to Casio calculators. If you need help determining which calculator is best for you, see our review guide here: How to Buy a Calculator.

You can find our review of the Casio FX: Casio FX Calculator Review.

### Example 1

Convert `56\ ∠\ 27^@` to rectangular form (*x* + *jy*), where `j=sqrt(-1)`.

Keystrokes |
Display |

`56` | `56` |

`56` | |

`27` | `27` |

`49.89636535 (= x)` | |

`25.42346799 (= y)` |

Therefore, `56\ ∠\ 27^@ ≈ 49.9 + 25.4 j`

We have converted a complex number from polar form (using degrees) into rectangular form.

Of course, you have to be careful that you have your
calculator set correctly in **degrees** (or radians, if
required).

### Example 2

Convert `12 - 42j` to polar form (`r ∠ theta`).

For **CASIO** calculator...

Keystrokes |
Display |

`12` | `12` |

`12` | |

`42` | `42` |

`-42` | |

`43.68065934 (= r)` | |

`-74.0546041 (= θ)` |

Therefore:

Complex number in **rectangular** form: `12 - 42j`

Same complex number in **polar** form: `43.7 ∠ -74^@`

For **Sharp** calculator, it is a similar
process.

Consult your calculator manual for full details.