In the following circuit i want to find the output voltage Vo related to the input Voltage Vi. Diodes D1 and D2 are the same and have a 0,7V drop when they conduct. Op-amp is ideal too. For the zener diode we know that: $$Vzener=8,6V$$
Well, when our input is positive (Vi>0) , the output Vo is negative(Vo<0), so Zener diode conducts but both D1 and D2 are reversed biased,so the circuit works as an inverting operational amplifer with Gain=-Rf/Rin=-10K/1K=-10. So Vo=-10Vi.
I am a bit confused with the other case about the negative input(Vi<0). Then the output will be positive(Vi>0). Will this make the zener diode conduct in the opposite direction and D1,D2 forward biased as well, so that we have another path from the output to the inverting input?