Engineers usually prefer to express the function as graphs rather than in algebraic form. 工程师通常喜欢把这些函数用图线来表示,而不愿意写成代数形式。
But to compute an economic model, this theory has to be given concrete form, spelt out in definite algebraic terms. 要想用一个经济模型来计算,那这个模型就必须要有具体的以代数形式给出的表达式。