Consider an example of biaxial stretch of an incompressible isotropic slab (see the lecture) under the conditions of infinitesimal strains 12=1+82, , where 81 <1, 82 <1, Assume that the material of the slab is neo-Hookean with the strain energy function where Cl is a constant. Derive the Cauchy stresses mand t22 as linear functions of 81, 82, and 83.