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The number of real roots of the equation...

The number of real roots of the equation `x^(2)- 3 |x| + 2 = 0` is :

A

(A)4

B

(B)3

C

(C)2

D

(D)1

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AI Generated Solution

The correct Answer is:
To find the number of real roots of the equation \( x^2 - 3|x| + 2 = 0 \), we will analyze the equation by considering two cases based on the definition of the absolute value function. ### Step 1: Define the cases for \( |x| \) The absolute value function \( |x| \) can be defined as: - \( |x| = x \) when \( x \geq 0 \) - \( |x| = -x \) when \( x < 0 \) ### Step 2: Case 1 - When \( x \geq 0 \) In this case, we replace \( |x| \) with \( x \): \[ x^2 - 3x + 2 = 0 \] Now, we will factor the quadratic equation: \[ (x - 1)(x - 2) = 0 \] This gives us the roots: \[ x = 1 \quad \text{and} \quad x = 2 \] Both roots \( x = 1 \) and \( x = 2 \) are valid since they are non-negative. ### Step 3: Case 2 - When \( x < 0 \) In this case, we replace \( |x| \) with \( -x \): \[ x^2 + 3x + 2 = 0 \] Now, we will factor this quadratic equation: \[ (x + 1)(x + 2) = 0 \] This gives us the roots: \[ x = -1 \quad \text{and} \quad x = -2 \] Both roots \( x = -1 \) and \( x = -2 \) are valid since they are negative. ### Step 4: Summary of Roots From both cases, we have found the following real roots: 1. From Case 1: \( x = 1, 2 \) 2. From Case 2: \( x = -1, -2 \) Thus, the total number of real roots of the equation \( x^2 - 3|x| + 2 = 0 \) is **4**. ### Final Answer The number of real roots of the equation \( x^2 - 3|x| + 2 = 0 \) is **4**. ---
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