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a. Robots can be used in manufacturing and assembly operations that require accurate, fast and versatile manipulation. The open loop transfer function of a unity feedback system of a direct drive arm may be approximated by, s5+2s4+3s3+6s2+5s+3K Assuming the gain to be positive, determine the range of K for stability of the closed loop system. Find the value of K that will cause sustained oscillation. At the gain of sustained oscillation, what is the natural frequency