Expression 2: "y" Subscript, 1 , Baseline tilde "a" "x" squared plus "b" "x" Subscript, 1 , Baseline plus "c"y1~ax21+bx1+c
2
Expression 3: "y" Subscript, 1 , Baseline tilde "a" "x" to the 4th power plus "b" "x" cubed plus "c" "x" squared plus "d" "x" Subscript, 1 , Baseline plus "e"y1~ax41+bx31+cx21+dx1+e