表达式4: "P" Subscript, 1 , Baseline left parenthesis, 1 minus "t" , right parenthesis plus left parenthesis, 7 , 1 , left bracket, "a" , negative "a" , right bracket , right parenthesis "t"P11−t+7,1,a,−at
定义域t最小值： negative 20−20
less than or equal to "t" less than or equal to≤t≤
定义域t最大值： 3030
4
表达式5: "a" equals 1a=1
negative 5−5
55
5
表达式6: 7 fifths left parenthesis, 4 , negative 3 , 0 , right parenthesis plus left parenthesis, 3 , 4 , 5 , right parenthesis "t"754,−3,0+3,4,5t
定义域t最小值： negative 3−3
less than or equal to "t" less than or equal to≤t≤
