Operational amplifiers and diodes

[portuguese]

Hi guys! I'm portuguese and I have an Electricity exam tomorrow. So this is really urgent. There are 2 kinds of exercises I don't know how to do. The tests usually have similar exercises to these ones:

1) Operational Amplifiers

Consider the circuit represented in this picture:

. The voltage vi(t)=1sin(wt) V and the operational amplifier saturates in (+-)12V. Calculate and plot the signal of the voltage vo(t).

2) Diodes

Consider this circuit:

. Plot the signal vo(t) (show your calculations [all of them]).

I really need your help! Thanks a lot!

 

[mister_rf]

;-)
https://www.edaboard.com/threads/254937/

 

[D.A.(Tony)Stewart]

I think Kirchhoff node summing equations gets the formula linked below.
But as an old guy, I take short-cuts so I wont get points on the exam..I just calculate in my head and see the results.

I would sum the product terms of input signal and gain for each source. to get the output and clip near the rails as indicated.
https://www.rfcafe.com/references/electrical/opamps.htm. But the prof may expect the sum of K's law equations.