Euler’s formula is one of those math ideas that feels almost too perfect to be real. It says that e to the power of i times x equals cos(x) plus i times sin(x). That might sound a bit technical, but what it really does is connect three very different parts of math—exponentials, imaginary numbers, and trigonometry—all in one clean equation. It shows up all over the place, from electrical engineering to quantum physics, and helps make sense of how waves and rotations work in the complex plane. One