Expression 5: "y" equals StartFraction, "a" Over 2 , EndFraction "t" squared plus "v" Subscript, "i" , Baseline "t" plus "d" Subscript, "i" , Baseline left brace, "t" greater than 0 , right bracey=a2t2+vit+dit>0
5
Expression 6: "y" equals "a" "t" plus "v" Subscript, "i" , Baseline left brace, "t" greater than 0 , right bracey=at+vit>0
6
Expression 7: "y" equals "a" left brace, "t" greater than 0 , right bracey=at>0