How to use the discriminant to find out how many real number roots an equation has for #-x^2 - 2x - 7 = -6#?
Jun 7, 2015
You don't need to find D. Use shortcut. Since a - b + c = 0, one real
root is (-1) and the other is
Note: y is a perfect square polynomial
y = -(x + 1)^2 --> double root --> x = -1