Edited my last question in order to contain the work I've done.

I have to find the output voltage Vo related to the input voltage Vi knowing that the input values range from 0V to 50V. All diodes are ideal.

I started by assuming that D3 is reversed biased. This means that D1 is forward biased and D2 is reversed biased if I am not mistaken.

So, I found VA= 3V (6V/2) using the voltage divider of the 2 5kΩ resistances. I made all this process in order to be able to define the range in which D3 conducts.

So, knowing that VA=3V, when D3 is OFF, I can say that D3 conducts when Ui>3V.

Then I got the range [3V,6V] where D3 and D1 are ON and D2 is OFF and found the output voltage related to the input voltage using the Millman's theorem.

Then I got the range [6V,20V], in which only D3 is ON , so again using a voltage divider on the simplified circuit with the 2 5kΩ and the 5kΩ resistances I found Vo=(2/3)Vi.

Finally I got the range [20V,50V] where both D3 and D2 are ON and D1 is OFF and again using a Millman's theorem found the output voltage.

However I don't know if this is the right way to approach this problem and i am not sure if my process is right. Any help is appreciated! Thanks in advance!

Edited my last question in order to contain the work I've done.

I have to find the output voltage Vo related to the input voltage Vi knowing that the input values range from 0V to 50V. All diodes are ideal.

I started by assuming that D3 is reversed biased. This means that D1 is forward biased and D2 is reversed biased if I am not mistaken.

So, I found VA= 3V (6V/2) using the voltage divider of the 2 5kΩ resistances. I made all this process in order to be able to define the range in which D3 conducts.

So, knowing that VA=3V, when D3 is OFF, I can say that D3 conducts when Ui>3V.

Then I got the range [3V,6V] where D3 and D1 are ON and D2 is OFF and found the output voltage related to the input voltage using the Millman's theorem.

Then I got the range [6V,20V], in which only D3 is ON , so again using a voltage divider on the simplified circuit with the 2,5kΩ and the 5kΩ resistances I found Vo=(2/3)Vi.

Finally I got the range [20V,50V] where both D3 and D2 are ON and D1 is OFF and again using a Millman's theorem found the output voltage.

However I don't know if this is the right way to approach this problem and i am not sure if my process is right. Any help is appreciated! Thanks in advance!

Edited my last question in order to contain the work I've done.

I have to find the output voltage Vo related to the input voltage Vi knowing that the input values range from 0V to 50V. All diodes are ideal. I started by assuming that D3 is reversed biased. This means that D1 is forward biased and D2 is reversed biased if i am not mistaken. So, i found VA= 3V (6V/2) using the voltage devider of the 2 5kΩ resistances. I made all this process in order to be able to define the range in which D3 conducts. So,knowing that VA=3V, when D3 is OFF, I can say that D3 conducts when Ui>3V. Then i got the range [3V,6V] where D3 and D1 are ON and D2 is OFF and found the output voltage related to the input voltage using the Millman's theorem. Then i got the range [6V,20V], in which only D3 is ON , so again using a voltage devider on the simplified circuit with the 2,5kΩ and the 5kΩ resistances i found Vo=(2/3)Vi. Finally i got the range [20V,50V] where both D3 and D2 are ON and D1 is OFF and again using a Millman's theorem found the output voltage. However i don't know if this is the right way to approach this problem and i am not sure if my process is right. Any help is appreciated! Thanks in advance!

Edited my last question in order to contain the work I've done.

I have to find the output voltage Vo related to the input voltage Vi knowing that the input values range from 0V to 50V. All diodes are ideal. 

I started by assuming that D3 is reversed biased. This means that D1 is forward biased and D2 is reversed biased if I am not mistaken. 

So, I found VA= 3V (6V/2) using the voltage divider of the 2 5kΩ resistances. I made all this process in order to be able to define the range in which D3 conducts. 

So, knowing that VA=3V, when D3 is OFF, I can say that D3 conducts when Ui>3V. 

Then I got the range [3V,6V] where D3 and D1 are ON and D2 is OFF and found the output voltage related to the input voltage using the Millman's theorem. 

Then I got the range [6V,20V], in which only D3 is ON , so again using a voltage divider on the simplified circuit with the 2 5kΩ and the 5kΩ resistances I found Vo=(2/3)Vi. 

Finally I got the range [20V,50V] where both D3 and D2 are ON and D1 is OFF and again using a Millman's theorem found the output voltage. 

However I don't know if this is the right way to approach this problem and i am not sure if my process is right. Any help is appreciated! Thanks in advance!