You can use several different constants in your mathematical expressions.

**Note**: When you enter constants multiplied by a number, make sure to indicate the multiplication explicitly. For example, enter `2*c`

instead of `2c`

, and enter `-4*i`

instead of `-4i`

.

Constant |
Value |

C | The speed of light in m/s (2.998^8) |

e | Euler’s number (2.718…) |

g | Gravity (9.80 m/s^2) |

i | The square root of -1 |

j | The square root of -1 |

k | The Boltzmann constant (~1.38^-23 in Joules/Kelvin) |

pi | The ratio of a circle’s circumference to its diameter (3.14159…) |

q | The fundamental charge (~1.602^-19 Coloumbs) |

T | The positive difference between 0K and 0°C (273.15) |