Math Problem Statement

Solution

The image shows the inequality:

(x21)(x24)0(x^2 - 1)(x^2 - 4) \leq 0

To solve this inequality, let's break it down into steps:

Step 1: Factorize the expressions

Both x21x^2 - 1 and x24x^2 - 4 are difference of squares, so we can factor them:

x21=(x1)(x+1)x^2 - 1 = (x - 1)(x + 1) x24=(x2)(x+2)x^2 - 4 = (x - 2)(x + 2)

So the inequality becomes:

(x1)(x+1)(x2)(x+2)0(x - 1)(x + 1)(x - 2)(x + 2) \leq 0

Step 2: Determine the critical points

The critical points, where the expression equals zero, occur at: x=2,1,1,2x = -2, -1, 1, 2

Step 3: Analyze the intervals

The critical points divide the number line into five intervals:

  1. (,2)(-\infty, -2)
  2. (2,1)(-2, -1)
  3. (1,1)(-1, 1)
  4. (1,2)(1, 2)
  5. (2,)(2, \infty)

We need to check the sign of the product (x1)(x+1)(x2)(x+2)(x - 1)(x + 1)(x - 2)(x + 2) within each interval.

Step 4: Check the sign in each interval

  • Interval (,2)(- \infty, -2): All four factors are negative, so the product is positive.
  • Interval (2,1)(-2, -1): x+2x + 2 is positive, and the others are negative, so the product is negative.
  • Interval (1,1)(-1, 1): x+2x + 2 and x+1x + 1 are positive, x1x - 1 and x2x - 2 are negative, so the product is positive.
  • Interval (1,2)(1, 2): x2x - 2 is negative, and the others are positive, so the product is negative.
  • Interval (2,)(2, \infty): All four factors are positive, so the product is positive.

Step 5: Identify where the product is less than or equal to zero

The product is negative or zero in the intervals (2,1)(-2, -1) and (1,2)(1, 2), including the critical points x=2,1,1,2x = -2, -1, 1, 2 where the product equals zero.

Final Answer:

The solution to the inequality is:

[ [-2, -1] \cup [1, 2] ]

Would you like any further details or have any questions?

Here are 5 questions that relate to this problem:

  1. How can inequalities with higher-degree polynomials be solved?
  2. What is the significance of the difference of squares in factorization?
  3. How do you determine the sign of a polynomial over an interval?
  4. How would the solution change if the inequality were strict (i.e., << instead of \leq)?
  5. What are some common mistakes when solving polynomial inequalities?

Tip: When solving polynomial inequalities, always check the sign of the product within each interval created by the critical points.

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Math Problem Analysis

Mathematical Concepts

Inequalities
Polynomials
Factorization
Critical Points
Sign Analysis

Formulas

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Theorems

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Suitable Grade Level

Grades 10-12