HP 40G manual Complex numbers, Converting a number to a fraction, + iy, To enter

Converting a number to a fraction

When converting a number to a fraction, keep the following points in mind:

•When converting a recurring decimal to a fraction, set the fraction precision to about 6, and ensure that you include more than six decimal places in the recurring decimal that you enter.

In this example, the fraction precision is set to 6. The top calculation returns the correct result. The bottom one does not.

•To convert an exact decimal to a fraction, set the fraction precision to at least two more than the number of decimal places in the decimal.

In this example, the fraction precision is set to 6.

Complex numbers

Complex results

To enter complex numbers

The HP 39G/40G can return a complex number as a result for some math functions. A complex number appears as an ordered pair (x, y), where x is the real part and y is the imaginary part. For example, entering – 1 returns (0,1).

Enter the number in either of these forms, where x is the real part, y is the imaginary part, and i is the imaginary constant, – 1 :

•(x, y) or

•x + iy

To enter i:

•press >6+,)7@>$/3+$@ I or

•press >0$7+@, *k,￿or *e,￿keys to select Constant, *A,￿ to move to the right column of the menu, *e,￿to￿select i, and 2.a.

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