Question

Find the value of k if x^2 - 2x - k = 0 has one solution

Answer 1

If x^2 - 2x - k = 0 has one solution, then the discriminant must be zero.

Answer 2

The discriminant is b^2 - 4 ac.

Answer 3

In this problem, a = 1, b = -2, and c = -k.

Answer 4

Take the equation b^2 - 4 ac = 0 and replace b by (-2), a by (1), and c by (-k).

You can then solve for k. Post what you get so we can check it together.

@Chad123

Answer 5

What did you get?

Answer 6

I got - 1 as my answer

Answer 7

K= -1

Answer 8

Thanks a lot

Answer 9

Yes. Let's see how it looks on the quadratic.

Answer 10

x^2 - 2x - k = 0
x^2 - 2x - (-1) = 0
x^2 - 2x + 1 = 0
(x -1)(x-1)=0
x = 1 or x = 1 ---> It works.