An op amp has two negative real open-loop poles with magnitudes 100 Hz and 120 kHz and a negative real zero with magnitude 100 kHz. The low frequency open-loop voltage gain of the op amp is 100 dB. If this amplifier is placed in a negative feedback loop, sketch the root locus as f varies from 0 to 1. Calculate the poles and zeros of the feedback amplifier for f = 10⁻³ and f = 1.