What is the value of b+c if x^2+bx+c>0 only when x is (-inf, -2) U (2, inf)?
)
The parabola tuurs upward and has roots at x = -2 and x = 2
So we have
(x + 2) (x - 2) > 0
x^2 - 4 > 0
b = 0
c = -4
b + c = 0 - 4 = -4