专业词汇 Professional terms Optimum Combination of Factors Isoquant least-cost Isocost curves price change shallow curve steep curve Marginal rate of factor substitution Isocost The expansion path optimum combination Point of tangencyOptimum Combination of Factors Isoquant least-cost Isocost curves price change shallow curve steep curve Marginal rate of factor substitution Isocost The expansion path optimum combination Point of tangency 专业词汇Professional terms