Math Problem Statement

(x^2)-x-6>0

Solution

To solve the inequality x2x6>0x^2 - x - 6 > 0, we can follow these steps:

1. Factor the quadratic expression:

First, we factor the quadratic equation x2x6x^2 - x - 6.

x2x6=(x3)(x+2)x^2 - x - 6 = (x - 3)(x + 2)

So, the inequality becomes:

(x3)(x+2)>0(x - 3)(x + 2) > 0

2. Determine the critical points:

The critical points are the values of xx that make the expression equal to zero. Set each factor equal to zero:

x3=0x=3x - 3 = 0 \quad \Rightarrow \quad x = 3 x+2=0x=2x + 2 = 0 \quad \Rightarrow \quad x = -2

These critical points divide the number line into three intervals: (,2)(-\infty, -2), (2,3)(-2, 3), and (3,)(3, \infty).

3. Test the intervals:

To determine where the expression is positive, test a point from each interval:

  • For x(,2)x \in (-\infty, -2), choose x=3x = -3: (33)(3+2)=(6)(1)=6>0(-3 - 3)(-3 + 2) = (-6)(-1) = 6 > 0

  • For x(2,3)x \in (-2, 3), choose x=0x = 0: (03)(0+2)=(3)(2)=6<0(0 - 3)(0 + 2) = (-3)(2) = -6 < 0

  • For x(3,)x \in (3, \infty), choose x=4x = 4: (43)(4+2)=(1)(6)=6>0(4 - 3)(4 + 2) = (1)(6) = 6 > 0

4. Write the solution:

The expression is positive in the intervals (,2)(-\infty, -2) and (3,)(3, \infty). Therefore, the solution to the inequality is:

x(,2)(3,)x \in (-\infty, -2) \cup (3, \infty)

Would you like further details or have any questions?

Related Questions:

  1. How do you solve inequalities involving absolute values?
  2. What are the steps to solve a quadratic equation by completing the square?
  3. How can you graph the solution set of x2x6>0x^2 - x - 6 > 0?
  4. What is the significance of the discriminant in quadratic equations?
  5. How do you solve a system of quadratic inequalities?

Tip:

Always check the sign of the product in each interval to ensure the correct solution set for inequalities involving products or quotients.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Inequalities

Formulas

Factoring of quadratic expressions
Critical points determination

Theorems

Sign analysis of product of factors

Suitable Grade Level

Grades 9-11