The ֿ¹ Command

Command Summary

Returns the reciprocal of a number (1 divided by the number). For matrices, finds the matrix inverse.

Command Syntax


Menu Location

Press [xֿ¹]

Calculator Compatibility


Token Size

1 byte

The ֿ¹ command returns the reciprocal of a number, equivalent to dividing 1 by the number (although reciprocals are sometimes more convenient to type). It also works for lists, by calculating the reciprocal of each element.

The ֿ¹ command can also be used on matrices, but it is the matrix inverse that is computed, not the reciprocal of each element. If [A] is an N by N (square) matrix, then [A]ֿ¹ is the N by N matrix such that [A][A]ֿ¹=[A]ֿ¹[A] is the identity matrix. ֿ¹ does not work on non-square matrices.

        {1 .5 .3333333333}
        [[3  -2]
         [-4 3 ]]

Much like the number 0 does not have a reciprocal, some square matrices do not have inverses (they are called singular matrices) and you'll get an error when you try to invert them.


Writing Aֿ¹B instead of B/A is sometimes beneficial when B is a complicated expression, because it allows you to take off closing parentheses of B. For example:

can be

This may be slower than dividing. There are also situations in which this optimization might lose precision, especially when the number being divided is large:


Error Conditions

Related Commands


Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-Noncommercial-No Derivative Works 2.5 License.