Momentum Equation: Shear Stress Terms in Cylindrical Coordinates

[@alisiahpush4953]

In part 3, the figure is correct, but when he derives the shear in theta-r direction, the sign in front of theTau_ theta-r should be "-" not "+". (See time 4:28 min.). Ultimately, it results in adding two shear terms (see 8:14 min) to get (2/r)(Tau_r-theta), which is the correct answer. The final result is correct. What am I missing? Please show my mistake, if any.