Compute the transformed reduced stiffness

Question

Response to the following:

Compute the transformed reduced stiffness for the material of Exercise 1 at θ = 45? and θ = 90?. Comment on the results.

Exercise 1:

Compute the reduced stiffness [Q] and compliance [S] matrices, and the intralaminar shear stiffness [Q∗ ] and compliance [S ∗ ] matrices for a lamina with E₁ = 35 GP a, E₂ = 3.5 GP a, ν₁₂ = 0.3, G₁₂ = 1.75 GP a, G₂₃ = 0.35 GP a.