The gain of the op-amp without feedback (so called "open loop" mode) is too high to be useful as an amplifier. But this high gain provides a very sharp threshold if we use the op amp as a switch or comparator (so called because it compares one voltage to another and gives an output signifying which is greater).
This will compare the function generator output with an adjustable threshold proficed by the 0-6V supply.
Set the function generator to produce a 4 V p-p, 100 Hz triangle wave.