Understanding Op Amp Node Voltage Analysis: Equation Differences at Node D

[seang]

Hey, I think I need a little help understanding node voltage analysis with ideal op amps. For the circuit I've attached, at node D, I wrote the equation

((1/1000) + (1/1000))Vd - (1/50000)Vc - (1/1000)Ve = 0

However my prof's equation for node D is:

((1/1000) + (1/1000))Vd - (1/1000)Ve = 0

I don't understand why he didn't include the Vc like I did. I understand that Va = Vc, but you can't just say Va = 0, can you?

thanks much, sean

 

[berkeman]

Where do the "1000" numbers come from? Can you label the resistors or show their values? And no, Va will not be zero unless the current source has Iout = 0.