The parabola has an x intercept of about 1.7 and -1.7 so if we can estimate that the 1.7 ^2 is about 3 then we can assume this is the answer because the sq root of 3 is then 1.7 If we were to have an equation that said (x+1.7)(x-1.7) we would know right away that it was the correct answer None of the other answers come close to that