# Hilbert's seventeenth problem

> When are rational functions sums of quotients of squares

**Wikidata**: [Q2496877](https://www.wikidata.org/wiki/Q2496877)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Hilbert's_seventeenth_problem)  
**Source**: https://4ort.xyz/entity/hilbert-s-seventeenth-problem


## References

1. Freebase Data Dumps. 2013