How to Solve Quadratic Equations
- Author: Noreen Niazi
- Last Updated on: August 22, 2023
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ToggleAs a math enthusiast, I know how frustrating solving quadratic equations can be, especially when you need to know the right method. In this comprehensive guide, I will walk you through the different methods you can use to solve quadratic equations.
Introduction to Quadratic Equations
It’s crucial to comprehend what quadratic equations are before we can begin to solve them. A quadratic equation is a second-degree polynomial equation in which the variable’s maximum power is two. It is portrayed as
$$ax^2 + bx + c = 0$$
where x is the variable, and a, b, and c are coefficients.
There are several ways to solve quadratic equations, including the quadratic formula, the square formula, and transforming the quadratic equation to vertex form.
Understanding the Different Methods to Solve Quadratic Equations
There are three common methods of solving quadratic equations: the quadratic formula, completing the square formula, and converting the quadratic equation to vertex form.
Solving Quadratic Equations Using the Quadratic Formula
The quadratic formula is a powerful tool used to solve quadratic equations. It’s represented as:
$$x =\frac{ -b ±\sqrt{ b^2 – 4ac}}{2a}$$
You need to know the values of a, b, and c to use the quadratic formula. Once you have these values, you can plug them into the quadratic formula and solve for x.
How to Convert a Quadratic Equation to Vertex Form
Converting a quadratic equation to vertex form helps to identify the vertex of the parabola. The vertex form of a quadratic equation is represented as:
$$y = a(x – h)^2 + k$$
Where (h, k) is the vertex of the parabola. You must complete the square to convert a quadratic equation to vertex form.
Solve Quadratic Equations Using Completing the Square Formula
Another approach to solving a quadratic equation is to complete the square formula. To apply this technique, you must do the following:
- Step 1: First, combine the constant terms and x terms.
- Step 2: Multiply both sides by the $$x^2$$ term’s coefficient.
- Step 3: Modify the right-hand side of the equation by adding and removing the square of the x term’s half-coefficient.
- Step 4: Construct a simplified version of the right-hand side of the equation in the form $$(x + a)^2 = b$$.
- Step 5: Determine x by taking the square roots of both sides of the equation.
Solve Quadratic Equations Using Factorization
Do you have trouble solving quadratic equations? Don’t worry; today, we will discuss factoring quadratic equations. This method for solving quadratic equations is well-liked and regarded as one of the simplest.
- Step 1:Determine whether the quadratic equation may be factored in as the initial step. To accomplish this, we must ascertain whether the equation has two elements that add to the variable term’s coefficient and multiply to create the constant term. If we find two such components, the equation can be factored in.
- Step 2: $$ax^2 + bx + c = 0$$ must be the quadratic equation. Having completed that, we may move on to factorizing the equation. We can start by identifying the components of the $$x^2$$ coefficient.We can start by identifying the components of the coefficient of $$x^2$$, “a”. Then, we must identify two components of the constant term “c” that contribute to the coefficient “b.” When these components are identified, we may rewrite the equation as $$(px + q)(rx + s) = 0$$, where p, q, r, and s are the identified factors.
- Step 3: After factoring in the quadratic equation, we can now solve for the variables by setting each component to zero. The x values that satisfy the equation will be revealed as a result. After that, we can confirm that the equation still holds by inserting our solutions into the original one.
Examples of Solving Quadratic Equations Using Factorization
To further grasp this, let’s look at an example. The quadratic formula $$x^2 + 7x + 10 = 0$$ is an example. The quadratic expression’s factors are $$x + 5$$ and $$x + 2$$, which must be found to solve this equation.
Following that, we solve for x by setting each factor to zero. Consequently, $$x + 5$$ or $$x + 2$$ equals zero. We obtain $$x = -5$$ or $$x = -2$$ after solving for x.
Consequently, the quadratic equation $$x^2 + 7x + 10 = 0$$ has solutions $$x = -5$$ and $$x = -2.$$
Examples of Solving Quadratic Equations Using Completing the Square Formula
Take the quadratic equation $$x^2 + 6x + 9 = 0$$ as an example.
- Step 1: Group the x terms and the constant terms. We have $$x^2 + 6x = -9$$
- Step 2: Divide both sides by the coefficient of the term. We have $$\frac{x^2 + 6x}{1} = \frac{-9}{1}$$
- Step 3: Add and subtract the square of half of the coefficient of the x term to the right-hand side of the equation. We have $$x^2+6x+(\frac{6}{2})^2-(\frac{6}{2})^2=-9+(\frac{6}{2})^2$$
- Step 4: Simplify the right-hand side of the equation and write it in the form $$(x + a)^2 = b.$$ We have $$(x + 3)^2 = 0$$
- Step 5: Take the square root of both sides of the equation and solve for x. We have $$x=3$$
Solving Quadratic Equations Using the Quadratic Formula - Step by Step Guide
Now, let’s take the quadratic equation $$2x^2 + 5x – 3 =0$$ as an example to solve using the quadratic formula.
- Step 1: Identify the values of a, b, and c. We have $$a = 2, b = 5,$$ and $$c = -3$$
- Step 2: Plug in the values of a, b, and c into the quadratic formula. We have $$x =\frac{-5 ± \sqrt{5^2 -4(2)(-3)}}{2(2)}$$
- Step 3: Simplify the equation. We have $$x = \frac{-5 ± \sqrt{49}}{4}$$
- Step 4: Solve for x. We have $$x = \frac{-5 + 7}{4}$$ or $$x = \frac{-5 – 7}{4}$$. Therefore, $$x = \frac{1}{2}$$ or $$x = -3$$.
Examples of Solving Quadratic Equations Using the Quadratic Formula
Let’s use the quadratic formula to solve the quadratic equation $$x^2 – 4x + 7 = 0$$.
Step 1: Determine the values of a, b, and c in step 1. A is equal to 1, B is -4, and C is 7.
Step 2: Enter the quadratic formula with a, b, and c values. The equation is $$x =\frac{4 ±\sqrt{(-4)^2 – 4(1)(7)}}{2(1)}$$
Step 3: Make the equation simpler. $$x = \frac{4 ± \sqrt{-12}}{2}$$ is the value.
Step 4: Find x’s value. $$x = \frac{4± 2i * \sqrt(3)}{2}$$ is the result. Consequently, $$x = 2 i * \sqrt{3}$$.
Comparing the Different Methods to Solve Quadratic Equations
There are benefits and drawbacks to each quadratic technique. For instance, the quadratic formula is simpler, whereas the precise but more complicated is completing the square formula. When attempting to locate the vertex of a parabola, it is helpful to convert a quadratic equation to vertex form.
Final Words
In conclusion, solving quadratic equations can be difficult, but with the appropriate approach, it becomes more doable. The various approaches to solving quadratic equations—including the quadratic formula, the square-root formula, and transforming the quadratic equation to vertex form—have all been discussed in this thorough tutorial. It is easy and efficient to solve quadratic problems through factorization. We may quickly solve for the variable x by identifying the elements of the quadratic expression and putting each factor equal to zero. So remember this technique the next time you see a quadratic problem and use it to solve it.
You will be able to solve quadratic problems with ease if you comprehend these techniques.