<p>本人在看Pindyck, Rubinfeld的微观经济学第三版,第三章练习第7题中关于求证天然气和油的问题,问什么能分别设需求函数为<span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';">Q</span>
                <span style="; VERTICAL-ALIGN: sub; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; POSITION: relative; TOP: 2pt; mso-spacerun: 'yes'; mso-text-raise: -2.0000pt;">G</span>
                <span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';"> = a </span>
                <span style="; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';">-</span>
                <span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';"> bP</span>
                <span style="; VERTICAL-ALIGN: sub; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; POSITION: relative; TOP: 2pt; mso-spacerun: 'yes'; mso-text-raise: -2.0000pt;">G</span>
                <span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';"> + eP</span>
                <span style="; VERTICAL-ALIGN: sub; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; POSITION: relative; TOP: 2pt; mso-spacerun: 'yes'; mso-text-raise: -2.0000pt;">O</span> <span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';"> </span> ，</p><p>供给函数为<span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';">Q</span>
                <span style="; VERTICAL-ALIGN: sub; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; POSITION: relative; TOP: 2pt; mso-spacerun: 'yes'; mso-text-raise: -2.0000pt;">G</span>
                <span style="; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';"> =</span>
                <span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';"> c + dP</span>
                <span style="; VERTICAL-ALIGN: sub; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; POSITION: relative; TOP: 2pt; mso-spacerun: 'yes'; mso-text-raise: -2.0000pt;">G</span>
                <span style="; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; mso-spacerun: 'yes';"> + gP</span>
                <span style="; VERTICAL-ALIGN: sub; FONT-STYLE: italic; FONT-FAMILY: 'Century Schoolbook'; LETTER-SPACING: -0.1pt; POSITION: relative; TOP: 2pt; mso-spacerun: 'yes'; mso-text-raise: -2.0000pt;">O</span> （O和G分别代表OIL和GAS）<font size="2">？这个题目比较初级，见笑了，希望各位高人能给予解答。</font></p><!--Element not supported - Type: 8 Name: #comment--><!--Element not supported - Type: 8 Name: #comment-->