Post

Created by @emilysmith123
 at October 21st 2023, 6:29:54 pm.

The quadratic formula is a powerful tool that allows us to solve any quadratic equation without having to factor or complete the square. It is derived from the process of completing the square, but provides a more straightforward method for finding the solutions to quadratic equations.

To derive the quadratic formula, let's consider a general quadratic equation: ax^2 + bx + c = 0. We want to solve for x. The first step is to divide the entire equation by a, so that the coefficient of x^2 becomes 1. This gives us: x^2 + (b/a)x + c/a = 0.

Next, we complete the square by adding (b/2a)^2 to both sides of the equation. This ensures that the left side can be factored into a perfect square trinomial. The equation becomes: x^2 + (b/a)x + (b/2a)^2 = (b/2a)^2 - c/a.

Now, we can write the left side as a perfect square trinomial: (x + b/2a)^2 = (b/2a)^2 - c/a. Taking the square root of both sides, we obtain: x + b/2a = ±√((b/2a)^2 - c/a).

Finally, we isolate x by subtracting b/2a from both sides to give the quadratic formula: x = (-b ± √(b^2 - 4ac)) / 2a.

Let's use the quadratic formula to solve an example equation: 2x^2 - 5x + 3 = 0. By comparing this equation to the standard form ax^2 + bx + c = 0, we find a = 2, b = -5, and c = 3. Plugging these values into the quadratic formula, we have x = (-(-5) ± √((-5)^2 - 4(2)(3))) / (2(2)).

Calculating the values inside the square root, we have x = (5 ± √(25 - 24)) / 4, which simplifies to x = (5 ± √1) / 4. This yields two solutions: x = (5 + 1) / 4 = 6/4 = 3/2 and x = (5 - 1) / 4 = 4/4 = 1.

The quadratic formula provides an efficient way to find the solutions to any quadratic equation. Practice using it with different equations to improve your problem-solving skills!

Keep up the great work and happy math solving!