Why do even the simplest calculators feature a square root key?

[Dieter]

(05-05-2018 06:39 AM)Dieter Wrote:  I have never seen anyone calculating a square root on such a calculator, so I wonder why this function exists at all.

First of all thank you very much for your replies so far.

Yes, it is obvious that there are useful applications for a √x key on a calculator. But for me the essential question is this:

Why is it the √ function and not another one that might be even more useful? For instance, if I were to design a simple calculator and I had to choose one single additional function, it would be the power function y^x. This is far more useful and it can even be used for calculating roots. Or, looking at the typical user of such calculators, why not add a percent function instead of a rarely used √x ? Is there a technical reason? I don't think that the typical user of such a calculator has to deal with the Pythagorean theorem very often. ;-)

Dieter