Expression 3: StartFraction, 1 Over left parenthesis, 1 plus "e" Superscript, negative left parenthesis, theta Subscript, 0 , Baseline plus theta Subscript, 1 , Baseline times "x" plus theta Subscript, 2 , Baseline times "x" squared , right parenthesis , Baseline , right parenthesis , EndFraction11+e−θ0+θ1·x+θ2·x2