Notes on the Euler formula – Eli Bendersky's website

Euler's identity

Euler's famous identity ties the "five fundamental constants of mathematics" together:

\[e^{i\pi}-1=0\]

The "-" should be a "+"

This identity is trivial to derive from the Euler formula, because:

\[e^{i\pi}=cos(\pi)+i sin(\pi)=1\]

And this "=1" should be "=-1"

Is it a deliberate mistake to provoke engagement?

Or have I got that completely wrong?