differential amplifier can be used as a subtractor as shown in the above
figure. If all resistors are equal in value, then the output voltage can be
derived by using superposition principle.
the output V01 due to V1
alone, make V2 = 0.
circuit of figure as shown in the above becomes a non-inverting amplifier
having input voltage V1/2 at the non-inverting input terminal and
the output becomes
the output V02 due to V2 alone (with V1
grounded) can be written simply for an inverting amplifier as
output voltage Vo due to both the inputs can be written as
Vo= V 01+ V 02= V 1@V2