Question

Why is the voltage gain of an ideal opamp infinity?

Answer 1

Non-inverting Operational Amplifier Configuration This then makes the voltage follower circuit ideal as a Unity Gain Buffer circuit because of its isolation properties. The advantage of the unity gain voltage follower is that it can be used when impedance matching or circuit isolation is more important than amplification as it maintains the signal voltage.
this the why the voltage gain of an ideal opamp infinity