Question

If the function f (2) 3x2 + bx + 2 has no real roots, which of the following could be the value of b? -7, -1, 8, 0

10​

Answer 1

b could be -1 or 0

Explanation:

f(x) = 3x^2 +bx+2

if it has no real roots, the discriminant must be less than zero

b^2 -4ac <0

a=3 b=b c=2

b^2 - 4(3)(2) <0

b^2 - 24 <0

b^2 < 24

Taking the square root of each side

b< 2 sqrt(6) and b > 2 sqrt(6)

b could be -1 or 0