Figure 4. is a three degree of freedom (DoF) SCARA type arm, in which the first joint (1) is a vertical prismatic joint followed by 2 vertical axis revolute joints (2 and 3). Answer the following questions: a) Explain the physical meaning of the Denavit-Hartenberg parameters. Write down the DH table for the robotic arm shown in Figure 6. [6 marks] b) Derive the forward kinematic equations using the DH parameters from the previous question. [8 marks] c) Explain the problem of singularities when computing inverse kinematics. What does this mean physically