How do you find the discriminant $x^2+2x-1$ ?

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Answer 1 · 2018-03-20T14:37:50

See a solution process below:

For $ax^2 + bx + c = 0$ , the values of $x$ which are the solutions to the equation are given by:

$x = (-b +- sqrt(b^2 - 4ac))/(2a)$

The discriminate is the portion of the quadratic equation within the radical: $color(blue)(b)^2 - 4color(red)(a)color(green)(c)$

If the discriminate is:
- Positive, you will get two real solutions
- Zero you get just ONE solution
- Negative you get complex solutions

To find the discriminant for this problem substitute:

$color(red)(1)$ for $color(red)(a)$

$color(blue)(2)$ for $color(blue)(b)$

$color(green)(-1)$ for $color(green)(c)$

$color(blue)(2)^2 - (4 * color(red)(1) * color(green)(-1)) =>$

$4 - (-4) =>$

$4 + 4 =>$

$8$

Therefore, this quadratic would have two real solutions.

How do you find the discriminant x^2+2x-1x^2+2x-1?