# How can we use radicals in real life?

May 24, 2015

European paper sizes are a good example of real world usage of a radical.

The ratio of the length of the longer side of A4 paper to the shorter side is a good approximation of $\sqrt{2}$. As a result, a sheet of A4 can be cut in half to produce two smaller sheets (size A5) with the same proportions as the A4 sheet.

May 24, 2015

Another real life example would be calculation of interest rates.

If the annual interest rate on your savings is 3% then the monthly interest rate would be:

(root(12)1.03 - 1.0)*100%