[MindYourDecisions] presents a Babylonian tablet dating back to around 1800 BC that shows that the hypotenuse of a unit square is the square root of two or 1.41421. How did they know that?

To find approximate solutions in decimal form, continue on with a calculator, adding and subtracting the square root to find the two solutions. \(x = -3 \pm \sqrt{19}\) The first solution is ...

Check to find the ‘power’ button on your own calculator. This is particularly useful when the index number is large. The square root of \({16}\) is \({4}\) (because \(4^2 = 4 \times 4 = 16\)).