Mathf loop between 2 floats?

Hello!

Does anyone know how to make two variables come and go in a determined time?

I tried Mathf.pingpong and Mathf.repeat but there was no result, what other way could I try?
thanks!

ClutchTorque = Mathf.SmoothStep(MaxClutchTorque, MinClutchTorque, Time.maximumDeltaTime);

You are probably looking for Mathf.Lerp