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Let a function f (x)= be such that f(x)=...

Let a function `f (x)=` be such that `f(x)=||x^(2)-3|-2|`.
Equation has 2 solutions if :

A

`lambda gt 2`

B

`lambda lt 2`

C

`1 lt lambda lt 2`

D

`lambda ge 2`

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The correct Answer is:
To solve the problem, we need to analyze the function \( f(x) = ||x^2 - 3| - 2| \) and determine the conditions under which the equation \( f(x) = \lambda \) has exactly 2 solutions. ### Step 1: Understand the function structure The function \( f(x) \) is composed of nested absolute values. We can break it down into parts: 1. \( g(x) = x^2 - 3 \) 2. \( h(x) = |g(x)| = |x^2 - 3| \) 3. \( f(x) = |h(x) - 2| = ||x^2 - 3| - 2| \) ### Step 2: Analyze the inner function \( g(x) \) The function \( g(x) = x^2 - 3 \) is a parabola that opens upwards with its vertex at \( (0, -3) \). It intersects the x-axis at \( x = \pm\sqrt{3} \). ### Step 3: Analyze the function \( h(x) \) The function \( h(x) = |x^2 - 3| \) will be: - \( h(x) = x^2 - 3 \) for \( x^2 \geq 3 \) (i.e., \( x \leq -\sqrt{3} \) or \( x \geq \sqrt{3} \)) - \( h(x) = -(x^2 - 3) = 3 - x^2 \) for \( -\sqrt{3} < x < \sqrt{3} \) ### Step 4: Analyze the function \( f(x) \) Now, we analyze \( f(x) = |h(x) - 2| \): 1. For \( x \leq -\sqrt{3} \) or \( x \geq \sqrt{3} \): - \( f(x) = |(x^2 - 3) - 2| = |x^2 - 5| \) 2. For \( -\sqrt{3} < x < \sqrt{3} \): - \( f(x) = |(3 - x^2) - 2| = |1 - x^2| \) ### Step 5: Determine the critical points - For \( f(x) = |x^2 - 5| \): - It equals 0 at \( x = \pm\sqrt{5} \). - It equals 2 at \( x^2 - 5 = 2 \) or \( x^2 = 7 \) (i.e., \( x = \pm\sqrt{7} \)). - For \( f(x) = |1 - x^2| \): - It equals 0 at \( x = \pm 1 \). - It equals 2 at \( 1 - x^2 = 2 \) or \( x^2 = -1 \) (not possible). ### Step 6: Sketch the graph of \( f(x) \) - The graph of \( f(x) \) will have a V-shape at the points where it equals 0 and will change slopes at \( x = \pm\sqrt{5} \) and \( x = \pm\sqrt{3} \). ### Step 7: Determine conditions for 2 solutions To have exactly 2 solutions for \( f(x) = \lambda \): - The horizontal line \( y = \lambda \) must intersect the graph of \( f(x) \) at exactly two points. - From the analysis, we find that: - If \( \lambda < 2 \), the line intersects at 4 points. - If \( \lambda = 2 \), the line intersects at 4 points. - If \( \lambda > 2 \), the line intersects at 2 points. ### Conclusion Thus, the equation \( f(x) = \lambda \) has exactly 2 solutions if: \[ \lambda > 2 \]
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