Math
It’s relatively simple, you look at the last digit and there is one to two numbers that could be in the ones place that if squared would give you the same number in the ones place. Then to find the other part of the number you take away the ones and tens places and find the square root (without going over) of the other places like they were a regular number. Then you put the numbers together and if you had a zero or five in the ones place you are done otherwise you use guess and check for one number and if it’s right then it is that number otherwise it is the other number.
s (in the complex frequency domain, also known as s-domain, or s-plane). The transform has many applications in science and engineering because it is a tool for solving differential equations. In particular, it transforms linear differential equations into algebraic equations and convolution into multiplication.”
I use to use Paul's online notes for some higher level math help...its been years but it might still be around