Solving quadratic equations ( finding the value of x)

In summary, to solve for the variable in a quadratic equation, you can factor, complete the square, or use the quadratic formula. The formula is useful to remember because it always works, even if you can't solve it using the other methods.
  • #1
Zyne
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Homework Statement



I just need some guidance regarding how to work out the value of x in the quadratic equation. I don't want you guys to do the work for me, I just want to know how to figure it out.
Thanks

Homework Equations





The Attempt at a Solution

 
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  • #2
This should probably be in the Precalculus forum...

For a given quadratic equation, you can solve for the variable by completing the square. Do you need more details than that?
 
  • #3
1) Factor if you can.

2) Complete the square

3) Use the quadratic formula.
 
  • #4
Remembering the quadratic formula is useful anyway, because it always works. Even if you think that you should be able to solve it using one of the other methods, but you really don't see it, you can always revert to writing down the quadratic formula and just plugging in the numbers.
 

FAQ: Solving quadratic equations ( finding the value of x)

What is a quadratic equation?

A quadratic equation is an algebraic equation that contains a variable raised to the second power (x^2) and includes a constant term and a linear term (x). It can be written in the form ax^2 + bx + c = 0, where a, b, and c are constants and a cannot be equal to 0.

How do you solve a quadratic equation?

There are several methods for solving a quadratic equation, including factoring, using the quadratic formula, and completing the square. The method used depends on the form of the equation and personal preference. However, the most commonly used method is the quadratic formula, which is x = (-b ± √(b^2 - 4ac)) / 2a.

What is the discriminant and how is it used to solve quadratic equations?

The discriminant is the expression b^2 - 4ac that appears under the square root in the quadratic formula. It helps determine the nature of the solutions to a quadratic equation. If the discriminant is positive, there are two distinct real solutions. If it is zero, there is one real solution. And if it is negative, there are no real solutions.

Can a quadratic equation have more than two solutions?

No, a quadratic equation can only have a maximum of two solutions. This is because a quadratic equation is a second-degree polynomial and, according to the fundamental theorem of algebra, a polynomial of degree n can have a maximum of n distinct solutions.

How do you check if a given value is a solution to a quadratic equation?

To check if a given value is a solution to a quadratic equation, simply substitute the value for x in the original equation and see if it satisfies the equation. If the resulting equation is true, then the value is a solution. If not, then it is not a solution.

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