Power (function): Difference between revisions

:''This page describes the dyadic arithmetic function. For the monadic natural exponential function (power of e), see [[Exponential]]. For the operator that iterates the function operand, see [[Power (operator)]].''

{{Built-in|Power|*}} is a [[dyadic]] [[scalar function]] which computes the [[wikipedia:exponentiation|exponentiation]] function of the two [[argument|arguments]]. More precisely, <source lang=apl inline>X*Y</source> computes X raised to the power of Y. Power shares the [[glyph]] <source lang=apl inline>*</source> with the monadic arithmetic function [[Exponential]].

A common technique is to choose [[sign]] based on [[Boolean]]s:

For positive integer Y, <source lang=apl inline>X*Y</source> equals the [[times|product]] of Y copies of X. When Y is 0, <source lang=apl inline>X*Y</source> equals 1, possibly except when X is also 0 (since [[wikipedia:zero to the power of zero|zero to the power of zero]] is undefined in mathematics).

[[negate|Negation]] on the power results in the [[reciprocal]] on the return value.

[[Reciprocal]] on the power results in the n-th root on the return value. This can be used to calculate the square root.