# If ab + bc + ca is equal or greater than 2, what is the minimum possible value for a^2 + b^2 + c^2? This was on a noncalculator paper

##### 1 Answer

Jun 24, 2018

2

#### Explanation:

We start with the identity

This shows that

(since a sum of squares of real numbers can not be negative)

Thus

Thus the minimum possible value for