Leonhard Euler (April 1707 – 18 September 1783) was a Swiss mathematician, physicist, astronomer, geographer, logician and engineer who founded the studies of graph theory and topology and made pioneering and influential discoveries in many other branches of mathematics such as analytic number theory, complex analysis, and infinitesimal calculus. He introduced much of modern mathematical terminology and notation, including the notion of a mathematical function. He is also known for his work in mechanics, fluid dynamics, optics, astronomy and music theory.
Euler is held to be one of the greatest mathematicians in history and the greatest of the 18th century. A statement attributed to Pierre-Simon Laplace expresses Euler's influence on mathematics: "Read Euler, read Euler, he is the master of us all." Carl Friedrich Gauss remarked: "The study of Euler's works will remain the best school for the different fields of mathematics, and nothing else can replace it." Euler is also widely considered to be the most prolific, with over 850 publications.
This is one of his most influental work.
• 47% cotton, 28% nylon, 25% polyester
• Structured, five-panel, high profile
• Flat bill
• Snapback closure
• Snapback closure
• Head circumference: 21⅝″–23⅝″ (53.3 cm–58.4 cm)
Size guide
| ONE SIZE | |
| A (inches) | 20 ½-⅝ |
| B (inches) | 4 ½ |
| C (inches) | 2 ⅝ |
| D (inches) | 7 ½ |
| ONE SIZE | |
| A (cm) | 52-2 |
| B (cm) | 11 |
| C (cm) | 7 |
| D (cm) | 19 |