The Sum of Squares
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
State
A sum of squares does not factor over the real numbers: no product of real-coefficient binomials multiplies back to a² + b².
Show
x² + 9 stays whole. Every candidate pair fails the multiply-back check — and for every real x, the value sits at 9 or above, never crossing zero.
Builds on
- Nothing — this is a starting point.
Unlocks
- Nothing yet depends on this.