Which Equation Is True For $x = -6$ And $x = 2$?A. $2x^2 - 16x + 12 = 0$ B. $2x^2 + 8x - 24 = 0$ C. $3x^2 - 4x - 12 = 0$ D. $3x^2 + 12x + 36 = 0$
Introduction
Quadratic equations are a fundamental concept in mathematics, and they play a crucial role in various fields such as physics, engineering, and economics. In this article, we will explore the concept of quadratic equations, their properties, and how to solve them. We will also discuss the different types of quadratic equations and provide examples to illustrate the concepts.
What are Quadratic Equations?
A quadratic equation is a polynomial equation of degree two, which means that the highest power of the variable (usually x) is two. The general form of a quadratic equation is:
ax^2 + bx + c = 0
where a, b, and c are constants, and x is the variable.
Properties of Quadratic Equations
Quadratic equations have several properties that make them useful in various applications. Some of the key properties include:
- Symmetry: Quadratic equations are symmetric about the vertical line x = -b/2a.
- Axis of Symmetry: The axis of symmetry is the vertical line x = -b/2a.
- Vertex: The vertex of a quadratic equation is the point on the graph where the axis of symmetry intersects the graph.
- Roots: The roots of a quadratic equation are the values of x that satisfy the equation.
Types of Quadratic Equations
There are several types of quadratic equations, including:
- Monic Quadratic Equations: A monic quadratic equation is a quadratic equation of the form x^2 + bx + c = 0.
- Non-Monic Quadratic Equations: A non-monic quadratic equation is a quadratic equation of the form ax^2 + bx + c = 0, where a ≠1.
- Perfect Square Quadratic Equations: A perfect square quadratic equation is a quadratic equation of the form (x + b)^2 = 0.
- Incomplete Quadratic Equations: An incomplete quadratic equation is a quadratic equation of the form ax^2 + bx = 0.
Solving Quadratic Equations
There are several methods for solving quadratic equations, including:
- Factoring: Factoring is a method of solving quadratic equations by expressing the equation as a product of two binomials.
- Quadratic Formula: The quadratic formula is a method of solving quadratic equations by using the formula x = (-b ± √(b^2 - 4ac)) / 2a.
- Graphing: Graphing is a method of solving quadratic equations by graphing the equation on a coordinate plane.
Which Equation is True for x = -6 and x = 2?
To determine which equation is true for x = -6 and x = 2, we need to substitute these values into each of the equations and solve for x.
Equation A: 2x^2 - 16x + 12 = 0
Substituting x = -6 into Equation A, we get:
2(-6)^2 - 16(-6) + 12 = 0 72 + 96 + 12 = 0 180 = 0
This is not true.
Substituting x = 2 into Equation A, we get:
2(2)^2 - 16(2) + 12 = 0 8 - 32 + 12 = 0 -12 = 0
This is not true.
Equation B: 2x^2 + 8x - 24 = 0
Substituting x = -6 into Equation B, we get:
2(-6)^2 + 8(-6) - 24 = 0 72 - 48 - 24 = 0 0 = 0
This is true.
Substituting x = 2 into Equation B, we get:
2(2)^2 + 8(2) - 24 = 0 8 + 16 - 24 = 0 0 = 0
This is true.
Equation C: 3x^2 - 4x - 12 = 0
Substituting x = -6 into Equation C, we get:
3(-6)^2 - 4(-6) - 12 = 0 108 + 24 - 12 = 0 120 = 0
This is not true.
Substituting x = 2 into Equation C, we get:
3(2)^2 - 4(2) - 12 = 0 12 - 8 - 12 = 0 -8 = 0
This is not true.
Equation D: 3x^2 + 12x + 36 = 0
Substituting x = -6 into Equation D, we get:
3(-6)^2 + 12(-6) + 36 = 0 108 - 72 + 36 = 0 72 = 0
This is not true.
Substituting x = 2 into Equation D, we get:
3(2)^2 + 12(2) + 36 = 0 12 + 24 + 36 = 0 72 = 0
This is not true.
Conclusion
In conclusion, the equation that is true for x = -6 and x = 2 is Equation B: 2x^2 + 8x - 24 = 0. This equation satisfies the condition that the sum of the roots is equal to -b/a, and the product of the roots is equal to c/a.
References
- [1] "Quadratic Equations" by Math Open Reference
- [2] "Quadratic Formula" by Khan Academy
- [3] "Graphing Quadratic Equations" by Purplemath
Additional Resources
- [1] "Quadratic Equations" by Wolfram MathWorld
- [2] "Quadratic Formula" by Mathway
- [3] "Graphing Quadratic Equations" by IXL
Quadratic Equations Q&A ==========================
Frequently Asked Questions
Q: What is a quadratic equation?
A: A quadratic equation is a polynomial equation of degree two, which means that the highest power of the variable (usually x) is two. The general form of a quadratic equation is:
ax^2 + bx + c = 0
where a, b, and c are constants, and x is the variable.
Q: What are the properties of quadratic equations?
A: Quadratic equations have several properties that make them useful in various applications. Some of the key properties include:
- Symmetry: Quadratic equations are symmetric about the vertical line x = -b/2a.
- Axis of Symmetry: The axis of symmetry is the vertical line x = -b/2a.
- Vertex: The vertex of a quadratic equation is the point on the graph where the axis of symmetry intersects the graph.
- Roots: The roots of a quadratic equation are the values of x that satisfy the equation.
Q: How do I solve a quadratic equation?
A: There are several methods for solving quadratic equations, including:
- Factoring: Factoring is a method of solving quadratic equations by expressing the equation as a product of two binomials.
- Quadratic Formula: The quadratic formula is a method of solving quadratic equations by using the formula x = (-b ± √(b^2 - 4ac)) / 2a.
- Graphing: Graphing is a method of solving quadratic equations by graphing the equation on a coordinate plane.
Q: What is the quadratic formula?
A: The quadratic formula is a method of solving quadratic equations by using the formula x = (-b ± √(b^2 - 4ac)) / 2a. This formula is used to find the roots of a quadratic equation.
Q: How do I use the quadratic formula?
A: To use the quadratic formula, you need to plug in the values of a, b, and c into the formula. The formula is:
x = (-b ± √(b^2 - 4ac)) / 2a
You need to simplify the expression under the square root and then solve for x.
Q: What is the difference between a monic quadratic equation and a non-monic quadratic equation?
A: A monic quadratic equation is a quadratic equation of the form x^2 + bx + c = 0, where a = 1. A non-monic quadratic equation is a quadratic equation of the form ax^2 + bx + c = 0, where a ≠1.
Q: How do I graph a quadratic equation?
A: To graph a quadratic equation, you need to plot the points on the graph and then draw a smooth curve through the points. You can use a graphing calculator or a computer program to graph the equation.
Q: What is the vertex of a quadratic equation?
A: The vertex of a quadratic equation is the point on the graph where the axis of symmetry intersects the graph. The vertex is the minimum or maximum point of the graph.
Q: How do I find the vertex of a quadratic equation?
A: To find the vertex of a quadratic equation, you need to use the formula x = -b/2a. This will give you the x-coordinate of the vertex. You can then plug this value into the equation to find the y-coordinate of the vertex.
Q: What is the axis of symmetry of a quadratic equation?
A: The axis of symmetry of a quadratic equation is the vertical line x = -b/2a. This line is the axis of symmetry of the graph.
Q: How do I find the axis of symmetry of a quadratic equation?
A: To find the axis of symmetry of a quadratic equation, you need to use the formula x = -b/2a. This will give you the x-coordinate of the axis of symmetry.
Q: What is the difference between a quadratic equation and a linear equation?
A: A quadratic equation is a polynomial equation of degree two, while a linear equation is a polynomial equation of degree one.
Q: How do I solve a system of quadratic equations?
A: To solve a system of quadratic equations, you need to use the quadratic formula to find the roots of each equation. You can then use the roots to find the solution to the system.
Q: What is the discriminant of a quadratic equation?
A: The discriminant of a quadratic equation is the expression under the square root in the quadratic formula. It is given by the formula b^2 - 4ac.
Q: How do I use the discriminant to solve a quadratic equation?
A: To use the discriminant to solve a quadratic equation, you need to plug in the values of a, b, and c into the formula b^2 - 4ac. If the discriminant is positive, the equation has two real roots. If the discriminant is zero, the equation has one real root. If the discriminant is negative, the equation has no real roots.
Q: What is the difference between a quadratic equation and a polynomial equation?
A: A quadratic equation is a polynomial equation of degree two, while a polynomial equation is a polynomial equation of any degree.
Q: How do I solve a polynomial equation?
A: To solve a polynomial equation, you need to use various methods such as factoring, the quadratic formula, and graphing.
Q: What is the difference between a quadratic equation and a rational equation?
A: A quadratic equation is a polynomial equation of degree two, while a rational equation is an equation that contains fractions.
Q: How do I solve a rational equation?
A: To solve a rational equation, you need to use various methods such as cross-multiplication and simplifying the fractions.
Q: What is the difference between a quadratic equation and a trigonometric equation?
A: A quadratic equation is a polynomial equation of degree two, while a trigonometric equation is an equation that contains trigonometric functions.
Q: How do I solve a trigonometric equation?
A: To solve a trigonometric equation, you need to use various methods such as using the unit circle and trigonometric identities.
Q: What is the difference between a quadratic equation and a logarithmic equation?
A: A quadratic equation is a polynomial equation of degree two, while a logarithmic equation is an equation that contains logarithmic functions.
Q: How do I solve a logarithmic equation?
A: To solve a logarithmic equation, you need to use various methods such as using the properties of logarithms and the quadratic formula.
Q: What is the difference between a quadratic equation and an exponential equation?
A: A quadratic equation is a polynomial equation of degree two, while an exponential equation is an equation that contains exponential functions.
Q: How do I solve an exponential equation?
A: To solve an exponential equation, you need to use various methods such as using the properties of exponents and the quadratic formula.
Q: What is the difference between a quadratic equation and a system of equations?
A: A quadratic equation is a polynomial equation of degree two, while a system of equations is a set of equations that contain multiple variables.
Q: How do I solve a system of equations?
A: To solve a system of equations, you need to use various methods such as substitution, elimination, and graphing.
Q: What is the difference between a quadratic equation and a matrix equation?
A: A quadratic equation is a polynomial equation of degree two, while a matrix equation is an equation that contains matrices.
Q: How do I solve a matrix equation?
A: To solve a matrix equation, you need to use various methods such as using matrix operations and the quadratic formula.
Q: What is the difference between a quadratic equation and a differential equation?
A: A quadratic equation is a polynomial equation of degree two, while a differential equation is an equation that contains derivatives.
Q: How do I solve a differential equation?
A: To solve a differential equation, you need to use various methods such as using separation of variables and the quadratic formula.
Q: What is the difference between a quadratic equation and a partial differential equation?
A: A quadratic equation is a polynomial equation of degree two, while a partial differential equation is an equation that contains partial derivatives.
Q: How do I solve a partial differential equation?
A: To solve a partial differential equation, you need to use various methods such as using separation of variables and the quadratic formula.
Q: What is the difference between a quadratic equation and a stochastic differential equation?
A: A quadratic equation is a polynomial equation of degree two, while a stochastic differential equation is an equation that contains random variables.
Q: How do I solve a stochastic differential equation?
A: To solve a stochastic differential equation, you need to use various methods such as using the Ito calculus and the quadratic formula.
Q: What is the difference between a quadratic equation and a nonlinear equation?
A: A quadratic equation is a polynomial equation of degree two, while a nonlinear equation is an equation that contains nonlinear terms.
Q: How do I solve a nonlinear equation?
A: To solve a nonlinear equation, you need to use various methods such as using numerical methods and the quadratic formula.
Q: What is the difference between a quadratic equation and a chaotic equation?
A: A quadratic equation is a polynomial equation of degree two, while a chaotic equation is an equation that contains chaotic behavior.
Q: How do I solve a chaotic equation?
A: To solve a chaotic equation, you need to use various methods such as using numerical methods and the quadratic formula.
Q: What is the difference between a quadratic equation and a fractal equation?
A: A quadratic equation is a polynomial equation of