My inverting amplifier isn't working the way I want it to.

Looks like it's working fine to me.

>>55700731
The top should be 4V as it is the differential of the two other

So you reduced the amplification to one, supply +2V at the inverting input and are surprised that you get -2V output?

>>55700656
delta of IN and Out is 4V not 2V(??), and i hope You have a negative Rail.

>>55700902
See >>55700758

>>55701147
4V is what it should be, but it's not what I measure. Hence the problem. Yes, the opamp is supplied with +-12v

The Output Voltage of such an inverting Amplifier is given by the Formula:
Uout = - (Uin/R1*R2)
provided that:
-the Input Voltages of the OpAmp are within the permissible range
-you meant GND=0V with that triangle.

go read up the datasheet

>>55701372
I know all that, the problem is that what I measure don't align with the expectation. 2+2 is 2 but should be 4.

>>55701433
Any more details on the construction?
Voltage within the Tolerances of the Resistors?

>>55701496
Yes the resistors should be fine. It is actual four identical circuits on the same quad opamp tl084ipt, and they all have this problem. It's really strange, like the act of measuring interferes with the circuit even though the measuring probes have huge resistance like normal. I measured both with a cheap multimeter, and that actually showed a plausible result. But I also measured with an oscilloscope, and that showed different results from the multimeter, it showed the results in OP pic which should be impossible. As the OP pic shows when I measure both IN and out individually to ground, they show correct result, but not when I measure them deferentially. It's not the oscilloscope that is broken either because when I actually use the circuit for what it is meant for (it's part of a DAC for laser projectors) the intensity of the projection is way too low, meaning that the signal from the DAC, which is the differential signal from the amplifier in question, is too low, like I measured with the oscilloscope.

I will try replacing the opamp