For what values of $b$ is $-2$ not in the range of the function $f(x)=x^2+bx+2$? Express your answer in interval notation.

ignore the dollar signs.

Guest Feb 12, 2019

#1**+1 **

This was answered the other day.....

if the discriminant is less than zero it will not be a real number

x^2+bx+2 = -2

x^2+bx+4 = 0 discriminant is b^2 - 4(ac) = b^2 - 4(1)(4) if this is less than zero it will meet the requirements of your Q

b^2-16 <0

b^2 <16

b< +-4 so the interval is (-4,4)

ElectricPavlov Feb 12, 2019