The quadratic formula provides a direct method to solve quadratic equations of the form ax2 + bx + c = 0. Here's a step-by-step guide:
Steps to Solve a Quadratic Equation Using the Quadratic Formula
The quadratic formula is:
x = (-b ± √(b2 - 4ac)) / (2a)
Step | Description |
---|---|
1. Identify a, b, and c | Rewrite the quadratic equation in the standard form: ax2 + bx + c = 0. Identify the coefficients a, b, and c. |
2. Substitute the values into the formula | Plug the values of a, b, and c into the quadratic formula: x = (-b ± √(b2 - 4ac)) / (2a). According to the reference, this step involves direct substitution of the identified coefficients. |
3. Simplify | Simplify the expression by performing the arithmetic operations, following the order of operations (PEMDAS/BODMAS). This includes simplifying the square root and the entire expression. |
Example
Let's solve the quadratic equation 2x2 + 5x - 3 = 0 using the quadratic formula.
-
Identify a, b, and c:
- a = 2
- b = 5
- c = -3
-
Substitute into the quadratic formula:
x = (-5 ± √(52 - 4 2 -3)) / (2 * 2)
-
Simplify:
x = (-5 ± √(25 + 24)) / 4
x = (-5 ± √49) / 4
x = (-5 ± 7) / 4This gives us two possible solutions:
- x1 = (-5 + 7) / 4 = 2 / 4 = 1/2
- x2 = (-5 - 7) / 4 = -12 / 4 = -3
Therefore, the solutions to the quadratic equation 2x2 + 5x - 3 = 0 are x = 1/2 and x = -3.