Homework:

1. Starting with hyperelastic material, first take x₂-x₃ plane as plane of material symmetry and obtain the stiffness matrix. Is this matrix the same as in Equation (3.20) ? Justify your answer.
   
   
2. Starting with the stiffness matrix obtained in the above problem, take x₁-x₃as an additional plane of symmetry and obtain the stiffness matrix. Is this matrix the same as in Equation (3.26)? Justify your answer.