AC and DC voltage are constant even though the frequency changes
I can't see your circuit since the server in my university blocks the domain of the image hosting site, but based from your comment "I connected a my circuit to a function generator and oscilloscope. My circuit is also connected to two resistors," I am assuming that those are the only components in your circuit so I will base my answer on that.

Resistor is a component that is NOT frequency dependent unlike capacitor \$X_{c} = \frac1{2pifC}\$ and inductor \$X_{L} = 2pifL\$. Following Ohm's law, \$V = IR\$, the voltage of the resistor will not change since \$X_{R} = R\$, in contrast with capacitor and inductor whose voltages will change over frequencies.

But if your circuit is RLC, RL, or RC, the total voltage should change in varying frequencies.