(a) Explain briefly the interpretation of , when we use lagrangian functions (2 points). (b) Explain briefly the meaning of "transitive" consumer preference (2 points). (c) Explain briefly the meaning of the non-satiation assumption (2 points). (d) Explain briefly what is an Engel Curve (2 points). (e) Explain briefly what is the marginal rate of substitution. Write the formula and explain briefly (2 points).