Exercise 25.6 [inverse-kinematics-exercise]

Consider the robot arm shown in Figure FigArm1. Assume that the robot’s base element is 70cm long and that its upper arm and forearm are each 50cm long. As argued on page inverse-kinematics-not-unique, the inverse kinematics of a robot is often not unique. State an explicit closed-form solution of the inverse kinematics for this arm. Under what exact conditions is the solution unique?