One of the five quadratics below has a repeated root. (The other four have distinct roots.) What is the repeated root?
x^2 - 2x + 1
x^2 - 4x - 4
x^2 + 6x - 9
x^2 + 26x + 25
x^2 - 5x + 4
x^2 -2x + 1 = (x - 1) (x -1) = (x -1)^2 has a repeated root of x = 1
Another way is to find the discriminant of each.....the discriminant that = 0 is the one with a repeated root