Question

quadratic equation

Answers

GPT-4o mini
A quadratic equation is a polynomial equation of the form:

\[ ax^2 + bx + c = 0 \]

where:
- \(x\) represents the variable or unknown,
- \(a\), \(b\), and \(c\) are constants with \(a \neq 0\) (if \(a = 0\), the equation is linear, not quadratic),
- \(a\) is the coefficient of \(x^2\),
- \(b\) is the coefficient of \(x\),
- \(c\) is the constant term.

### Solving Quadratic Equations

There are several methods to solve a quadratic equation, including:

1. **Factoring**: If the quadratic can be factored, it can be expressed as:
\[
(px + q)(rx + s) = 0
\]
You can then set each factor equal to zero and solve for \(x\).

2. **Completing the Square**: This involves rearranging the equation into a perfect square form:
\[
ax^2 + bx + c = 0 \implies a\left(x + \frac{b}{2a}\right)^2 = \frac{b^2 - 4ac}{4a}
\]

3. **Quadratic Formula**: The roots can be found using the formula:
\[
x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}
\]
This method works for any quadratic equation.

### Example

Consider the quadratic equation:

\[ 2x^2 + 3x - 5 = 0 \]

Using the quadratic formula where \(a = 2\), \(b = 3\), and \(c = -5\):

1. Calculate the discriminant:
\[
D = b^2 - 4ac = 3^2 - 4 \cdot 2 \cdot (-5) = 9 + 40 = 49
\]

2. Apply the quadratic formula:
\[
x = \frac{-3 \pm \sqrt{49}}{2 \cdot 2} = \frac{-3 \pm 7}{4}
\]

Thus, the two possible solutions are:
\[
x = \frac{4}{4} = 1 \quad \text{and} \quad x = \frac{-10}{4} = -2.5
\]

### Conclusion

Quadratic equations are central to algebra and can model a wide variety of phenomena. Choosing the right method for solving them depends on the specific equation you are dealing with. If you have a specific equation you want to solve, feel free to provide it!