Fermat's theorem (disambiguation)

The mathematician Pierre de Fermat made many important discoveries in his career. Multiple theorems are named after him.

Theorems named after Fermat

In number theory:

• Fermat's Last Theorem, a conjecture on integers $a^{n}+b^{n}=c^{n}$
• Fermat's little theorem, on prime numbers in modular arithmetic
• Fermat's theorem on prime sums of squares, on what prime numbers can or can't be written as sums of perfects quares
• Fermat's polygonal number theorem, on integers as sum of polygonal numbers
• Fermat's right triangle theorem, on squares not being the difference of fourth powers

In calculus:

• Fermat's theorem (stationary points), on the value of the derivative at maximum and minimum points

In optics:

• Fermat's principle, an explanation of refraction