Euler’s identity is a mathematical beauty that ties five fundamental mathematical constants in mathematics together. In the equation, we have e, the base of natural logarithms, i, the imaginary unit, π, the ratio of the circumference of a circle to its diameter. This identity shows a profound connection between the most fundamental numbers in mathematics.
Math Textbook with Cat Pictures
Sheldon Axler is a funny math professor and he put his cats' pictures into his math textbook, Precalculus: A Prelude to Calculus.