Comment by thrtythreeforty

Here's another good reason to think in turns: it turns Euler's formula from this Eldritch Terror:

    e^(i*x) = cos(x) + i*sin(x)

into something you can kinda understand by staring at the complex plane:

    -1^(2x) = cost(x) + i*sint(x)

Credit to justinpombrio for this: https://news.ycombinator.com/item?id=32986869