How do you find a number that is the sum of two squares and whose square is also the sum of two squares?

1 Answer
Jul 31, 2017

If you take any two numbers, square them and add the squares, then the resulting number will satisfy your criteria.

Explanation:

Choose two numbers a and b.

Then:

(a^2-b^2)^2 + (2ab)^2 = (a^4-2a^2b^2+b^4) + 4a^2b^2

color(white)((a^2-b^2)^2 + (2ab)^2) = a^4+2a^2b^2+b^4

color(white)((a^2-b^2)^2 + (2ab)^2) = (a^2+b^2)^2

That is (a^2+b^2)^2 is the sum of two squares too.