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

The four stamps, issued by China Post, each depicts pi the mathematical constant, the Pythagorean theorem, Euler's formula and Mobius strip. [Photo by Jiang Dong/China Daily] They are enthralled ...

Instead of memorizing several complicated trig formulas, you need only one equation to rule them all: Euler's 1740 formula. With decent algebra skills, you can manipulate Euler's formula to see ...