It says:
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?