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If |x^(2) - 3 x + 2| gt x^(2) - 3 x + 2....

If `|x^(2) - 3 x + 2| gt x^(2) - 3 x + 2`. Then which one of the following is correct ?

A

`x le or x ge 2`

B

`1 le x le 2`

C

`1 lt x lt 2`

D

x is any real value except 3 and 4

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AI Generated Solution

The correct Answer is:
To solve the inequality \( |x^2 - 3x + 2| > x^2 - 3x + 2 \), we will analyze the expression in three different cases based on the critical points where the expression inside the absolute value changes sign. ### Step 1: Identify the critical points The expression \( x^2 - 3x + 2 \) can be factored as: \[ x^2 - 3x + 2 = (x - 1)(x - 2) \] The critical points are \( x = 1 \) and \( x = 2 \). These points will help us divide the number line into intervals for testing. ### Step 2: Analyze the intervals We will consider three cases based on the intervals created by the critical points: 1. **Case 1**: \( x \leq 1 \) 2. **Case 2**: \( 1 < x < 2 \) 3. **Case 3**: \( x \geq 2 \) ### Step 3: Case 1: \( x \leq 1 \) In this interval, \( x^2 - 3x + 2 \) is non-positive (since it is zero at \( x = 1 \) and negative for \( x < 1 \)). Therefore, we have: \[ |x^2 - 3x + 2| = -(x^2 - 3x + 2) = -x^2 + 3x - 2 \] The inequality becomes: \[ -x^2 + 3x - 2 > x^2 - 3x + 2 \] Simplifying this gives: \[ -2x^2 + 6x - 4 > 0 \quad \Rightarrow \quad 2x^2 - 6x + 4 < 0 \] Factoring or using the quadratic formula, we find the roots: \[ x = \frac{6 \pm \sqrt{(-6)^2 - 4 \cdot 2 \cdot 4}}{2 \cdot 2} = \frac{6 \pm \sqrt{36 - 32}}{4} = \frac{6 \pm 2}{4} \] This gives us the roots \( x = 2 \) and \( x = 1 \). The quadratic opens upwards, so it is negative between the roots: \[ 1 < x < 2 \] However, since we are in the case \( x \leq 1 \), there are no valid solutions here. ### Step 4: Case 2: \( 1 < x < 2 \) In this interval, \( x^2 - 3x + 2 \) is negative. Thus: \[ |x^2 - 3x + 2| = -(x^2 - 3x + 2) = -x^2 + 3x - 2 \] The inequality becomes: \[ -x^2 + 3x - 2 > x^2 - 3x + 2 \] This simplifies to: \[ -2x^2 + 6x - 4 > 0 \quad \Rightarrow \quad 2x^2 - 6x + 4 < 0 \] We already found the roots are \( x = 1 \) and \( x = 2 \). The quadratic is negative between these roots: \[ 1 < x < 2 \] This case is valid. ### Step 5: Case 3: \( x \geq 2 \) In this interval, \( x^2 - 3x + 2 \) is non-negative. Therefore: \[ |x^2 - 3x + 2| = x^2 - 3x + 2 \] The inequality becomes: \[ x^2 - 3x + 2 > x^2 - 3x + 2 \] This simplifies to: \[ 0 > 0 \] This is false, so there are no solutions in this case. ### Conclusion The only valid solutions are in Case 2, where \( 1 < x < 2 \). ### Final Answer The correct option is that \( x \) lies in the interval \( (1, 2) \).
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