9.3. The cross section a thin tube having variable wall thickness (t) is shown in the figure. The median line of the cross section is a circle of radius (r), and the thickness is given by the equation t = to (1 + sin()) where to is the thickness at the section where ẞ = 0. If the tube is subjected to a torque T, what is the maximum shear stress Tmax ? Minimum shear stress Tmin? Angle of twist 0? 210- Figure (3)