Mathematicians once turned up their noses at imaginary numbers. But complex analysis actually simplifies math and physics.

To a nonmathematician, having the letter “i” represent a number that does not quite exist and is “imaginary” can be ... Even Leonhard Euler, one of the greatest mathematicians, supposedly ...

To a nonmathematician, having the letter "i" represent a number that does not quite exist and is "imaginary" can be hard ... one equation to rule them all: Euler's 1740 formula.

Euler's formula relies on imaginary ... numbers makes it possible to use them in calculus. Fourier series allow periodic functions (blue) to be approximated by sums of sine and cosine functions ...