İ couldn't understand the answerNotice that the case of Vin = 0 V marks a discontinuity in the claimed output waveform. So it's value exactly at Vin = 0 V is not really defined. You need to look at the case when Vin = 0- V (i.e., a small negative voltage) and Vin = 0+ V (i.e., a small positive voltage).
As for why it's a squarewave, if Vin > 0 V, what is the output Y if Vin is supplying current and the opamp is within it's active region? Now look at the waveform for Vx when Vin < 0 V. Do you understand why it is what it is? What is the output Y if Vx is anything less than 0 V?
by Aaron Carman
by Duane Benson
by Duane Benson