Applets below show root locus for 1 pole and 1 pole, 1 zero systems.

For a 1 pole system with open loop pole at a, the closed loop is at -(a + K).

For a 1 pole 1 zero system with open loop pole at a and zero at z, the closed loop is at -(a + zK)/(1 + K).

Gif image below show how applet should appear.

COPYRIGHT © 2006 Cuthbert Nyack.