root (of an equation)

NOVEMBER 14, 2023

What is root (of an equation) in math? Definition

In mathematics, the root of an equation refers to the value(s) that satisfy the equation when substituted into it. It is the value(s) that make the equation true. The root is also known as the solution or the zero of the equation.

History of root (of an equation)

The concept of finding roots of equations dates back to ancient civilizations. The Babylonians, Egyptians, and Greeks all had methods for solving equations, including finding their roots. However, the formal study of roots and equations began in the 16th century with the works of mathematicians like François Viète and René Descartes.

What grade level is root (of an equation) for?

The concept of roots of equations is typically introduced in middle school or early high school mathematics. It is a fundamental topic in algebra and is covered in various grades depending on the curriculum.

What knowledge points does root (of an equation) contain? And detailed explanation step by step.

To understand roots of equations, one should have a solid understanding of algebraic expressions, equations, and basic arithmetic operations. The step-by-step process of finding roots involves:

  1. Start with an equation in the form f(x) = 0, where f(x) is a polynomial or any other mathematical expression.
  2. Simplify the equation if necessary by combining like terms or applying algebraic operations.
  3. Use various methods, such as factoring, completing the square, or using the quadratic formula, to isolate the variable and solve for its value(s).
  4. Substitute the found values back into the original equation to verify if they satisfy the equation and are indeed the roots.

Types of root (of an equation)

There are different types of roots based on the degree of the equation:

  1. Linear equation: A linear equation of the form ax + b = 0 has a single root, which is a real number.
  2. Quadratic equation: A quadratic equation of the form ax^2 + bx + c = 0 has two roots, which can be real or complex numbers.
  3. Cubic equation: A cubic equation of the form ax^3 + bx^2 + cx + d = 0 has three roots, which can be real or complex numbers.
  4. Higher-degree equations: Equations of degree four or higher can have multiple roots, and their nature depends on the specific equation.

Properties of root (of an equation)

Some important properties of roots of equations include:

  1. The sum of the roots of a quadratic equation is equal to the negative coefficient of the linear term divided by the coefficient of the quadratic term.
  2. The product of the roots of a quadratic equation is equal to the constant term divided by the coefficient of the quadratic term.
  3. The roots of a quadratic equation can be real or complex conjugates of each other.
  4. The roots of a cubic equation can be real or complex, and their sum and product can be determined using Viète's formulas.

How to find or calculate root (of an equation)?

To find or calculate the roots of an equation, various methods can be used depending on the type of equation. Some common methods include:

  1. Factoring: If the equation can be factored, the roots can be found by setting each factor equal to zero.
  2. Completing the square: This method is used for solving quadratic equations by manipulating the equation to create a perfect square trinomial.
  3. Quadratic formula: The quadratic formula provides a direct way to find the roots of any quadratic equation.
  4. Synthetic division: This method is used to find the roots of polynomial equations by dividing the polynomial by a potential root.
  5. Newton's method: This iterative method can be used to approximate the roots of any equation by making successive approximations.

What is the formula or equation for root (of an equation)?

The formula or equation for finding the roots of a quadratic equation is known as the quadratic formula:

x = (-b ± √(b^2 - 4ac)) / (2a)

Here, a, b, and c are the coefficients of the quadratic equation ax^2 + bx + c = 0.

How to apply the root (of an equation) formula or equation?

To apply the quadratic formula, substitute the values of a, b, and c into the formula and simplify. The resulting expression will give the values of x, which are the roots of the quadratic equation.

What is the symbol or abbreviation for root (of an equation)?

The symbol for the root of an equation is √. It represents the principal square root of a number or the positive root of a quadratic equation.

What are the methods for root (of an equation)?

The methods for finding the roots of an equation include factoring, completing the square, using the quadratic formula, synthetic division, and iterative methods like Newton's method. The choice of method depends on the type and complexity of the equation.

More than 3 solved examples on root (of an equation)

Example 1: Solve the equation x^2 - 5x + 6 = 0.

Using factoring, we can rewrite the equation as (x - 2)(x - 3) = 0. Setting each factor equal to zero, we get x - 2 = 0 and x - 3 = 0. Solving these equations, we find x = 2 and x = 3. Therefore, the roots of the equation are x = 2 and x = 3.

Example 2: Solve the equation 2x^2 + 5x + 2 = 0.

Using the quadratic formula, we have x = (-5 ± √(5^2 - 4(2)(2))) / (2(2)). Simplifying, we get x = (-5 ± √(25 - 16)) / 4. Further simplifying, we have x = (-5 ± √9) / 4. Taking the square root, we get x = (-5 ± 3) / 4. So, x = (-5 + 3) / 4 or x = (-5 - 3) / 4. Simplifying, we find x = -1/2 or x = -2. Therefore, the roots of the equation are x = -1/2 and x = -2.

Example 3: Solve the equation x^3 - 6x^2 + 11x - 6 = 0.

Using synthetic division, we can find that x = 1 is a root of the equation. Dividing the equation by (x - 1), we obtain (x - 1)(x^2 - 5x + 6) = 0. Factoring the quadratic equation, we have (x - 1)(x - 2)(x - 3) = 0. Setting each factor equal to zero, we get x - 1 = 0, x - 2 = 0, and x - 3 = 0. Solving these equations, we find x = 1, x = 2, and x = 3. Therefore, the roots of the equation are x = 1, x = 2, and x = 3.

Practice Problems on root (of an equation)

  1. Solve the equation 3x - 7 = 2x + 5.
  2. Find the roots of the equation x^2 + 4x + 4 = 0.
  3. Solve the equation 2x^3 - 5x^2 + 3x - 1 = 0.

FAQ on root (of an equation)

Question: What is the root of an equation? Answer: The root of an equation refers to the value(s) that satisfy the equation when substituted into it. It is the value(s) that make the equation true.

Question: How do you find the roots of a quadratic equation? Answer: The roots of a quadratic equation can be found using the quadratic formula or by factoring the equation.

Question: Can an equation have more than one root? Answer: Yes, an equation can have multiple roots depending on its degree and nature. For example, a quadratic equation can have two roots, while a cubic equation can have three roots.

Question: What is the difference between a root and a solution of an equation? Answer: The terms "root" and "solution" are often used interchangeably and refer to the same concept. Both represent the value(s) that satisfy the equation and make it true.