11. He is well known for his research in analysis and the calculus of variations . 12. His main fields of research are the calculus of variations and geometric measure theory. 13. This may be expressed mathematically using the calculus of variations 14. By the fundamental lemma of the calculus of variations , the integrand must vanish identically: 15. And, yes I'm aware that it is absolutely fundamental in the calculus of variations . 16. The method became known as " the royal road to the calculus of variations ". 17. Euler invented the calculus of variations including its most well-known result, the Euler Lagrange equation. 18. :There are other meanings of the word such as lambda calculus or calculus of variations . 19. :In general, the techniques for functional optimization problems are those of the calculus of variations . 20. He was honored for solving, in 1930, the inverse problem of the calculus of variations .
