According to Hooke's law, within the elastic limit stress/strain `=` constant. This constant depends on the type of strain or the type of force acting. Tensile stress might result in compressional or elongative strain, however, a tangential stress can only cause a shearing strain. After crossing the elastic limit, the material undergoes elongation and beyond a stage beaks. All modulus of elasticity are basically constants for the materials under stress.
If stress/strain is `x` in elastic region and `y` in the region of yield, then