#### 1.2.1 Elementary Calculations ¶

Octave can easily be used for basic numerical calculations. Octave knows about arithmetic operations (+,-,*,/), exponentiation (^), natural logarithms/exponents (log, exp), and the trigonometric functions (sin, cos, …). Moreover, Octave calculations work on real or imaginary numbers (i,j). In addition, some mathematical constants such as the base of the natural logarithm (e) and the ratio of a circle’s circumference to its diameter (pi) are pre-defined.

For example, to verify Euler’s Identity,

     i*pi
    e     = -1

type the following which will evaluate to `-1` within the tolerance of the calculation.

    octave:1> exp (i*pi)