5 ms·

But then how do you define the sine function?

• xigoi 4y ago
  Either in terms of the exponential function, or by its Taylor series.
  • doliveira 4y ago
    Oh yes, much simpler. I guess you can get to "i" via algebraic equations, but linking it to a rotation unit outside a flat space seems tricky.
    • xigoi 4y ago
      It's basic calculus. I'm really curious how you define the perimeter of a circle without basic calculus.
      • doliveira 4y ago
        Of course you can define it, but it's hard to justify the specific definition without a flat geometry. And you don't need proper calculus for the circumference, just the idea of limits.