Nikola Tesla was an extraordinary, but very eccentric inventor. His rivalries with Thomas Edison are famous. He died more than 75 years ago, but his discoveries and ideas have helped shape modern electricity, including Wireless Power.
Most of us probably have never used the hyperbolic tangent function tanh(x) or the sin(arctan(x)) reference function since our university days. But these functions enable a kinematic controller. Kinematics determines the position and orientation movement of an end-effector on a robotic arm as a function of the joint coordinates.