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

[hibiki]

Sometimes I use a simple calculator with square root function to calculate the absolute value of electrical impedances (polar form) when in rectangular a+jb format. It uses the pythagorean formula. Also it is suitable to calculate the ressonance frequency of a LC filter f=1/(2.PI. SQR(LC)) PI is typed 3.14159.
If you wish to have an idea of the length of sides of an squared area, the square root function is always welcome. I use a lot to calculate the diameter of copper wire from its section circular area.
Another use of square root function useful for me is to calculate the impedance ratios of output audio transformers and the voltage ratios n = SQR (Zp/Zs).
Some basic electrical formulas use square root function: I = SQR (P / R) V = SQR (P x R)
In electronics, the most of formulas do not need a scientific calculator, but a simple calculator with square root is enough.

I can think also for calculation of quadratic functions roots, as is needed to calculate the SQR (b^2-4ac) as a part of the formula.
Finally, with the square root function is possible to do the cubic root calculation of a number, using few iterations steps.