表达式4: left parenthesis, 1 plus 4 thirds "t" , 0.2 , right parenthesis1+43t,0.2
00
定义域t最小值：
less than or equal to "t" less than or equal to≤t≤
11
定义域t最大值：
4
表达式5: "h" left parenthesis, "x" , right parenthesis less than "y" less than 0.2 left brace, 1 less than "x" less than 2 , right bracehx<y<0.21<x<2
5
表达式6: 0.2 less than "y" less than "h" left parenthesis, "x" , right parenthesis left brace, 1 less than "x" less than 5 thirds , right brace0.2<y<hx1<x<53
6
表达式7: "x" equals left bracket, 1 , 5 , right bracketx=1,5
