# fundamental lemma of calculus of variations

> initial result in using test functions to find extremum

**Wikidata**: [Q2474925](https://www.wikidata.org/wiki/Q2474925)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Fundamental_lemma_of_the_calculus_of_variations)  
**Source**: https://4ort.xyz/entity/fundamental-lemma-of-calculus-of-variations


## References

1. Freebase Data Dumps. 2013