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If f(x)={{:(3-x^(2)",",xle2),(sqrt(a+14)...

If `f(x)={{:(3-x^(2)",",xle2),(sqrt(a+14)-|x-48|",",xgt2):}` and if f(x) has a local maxima at x = 2, then greatest value of a is

A

2013

B

2012

C

2011

D

2010

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we need to analyze the function \( f(x) \) and the condition for local maxima at \( x = 2 \). ### Step 1: Define the function The function is given as: \[ f(x) = \begin{cases} 3 - x^2 & \text{if } x \leq 2 \\ \sqrt{a + 14} - |x - 48| & \text{if } x > 2 \end{cases} \] ### Step 2: Evaluate \( f(2) \) First, we need to find \( f(2) \) using the first part of the function: \[ f(2) = 3 - 2^2 = 3 - 4 = -1 \] ### Step 3: Find the limit as \( x \) approaches 2 from the right Next, we need to evaluate the limit of \( f(x) \) as \( x \) approaches 2 from the right: \[ \lim_{h \to 0} f(2 + h) = \lim_{h \to 0} \left( \sqrt{a + 14} - |(2 + h) - 48| \right) \] Since \( 2 + h \) is greater than 2, we can simplify the absolute value: \[ |2 + h - 48| = |h - 46| = 46 - h \quad \text{(as } h \text{ approaches } 0\text{)} \] Thus, \[ \lim_{h \to 0} f(2 + h) = \sqrt{a + 14} - (46 - h) = \sqrt{a + 14} - 46 + h \] Taking the limit as \( h \to 0 \): \[ \lim_{h \to 0} f(2 + h) = \sqrt{a + 14} - 46 \] ### Step 4: Set up the condition for local maxima For \( f(x) \) to have a local maximum at \( x = 2 \), we need: \[ \lim_{h \to 0} f(2 + h) \leq f(2) \] This gives us: \[ \sqrt{a + 14} - 46 \leq -1 \] ### Step 5: Solve the inequality Rearranging the inequality: \[ \sqrt{a + 14} \leq 45 \] Squaring both sides: \[ a + 14 \leq 2025 \] Thus, \[ a \leq 2025 - 14 \] \[ a \leq 2011 \] ### Conclusion The greatest value of \( a \) such that \( f(x) \) has a local maximum at \( x = 2 \) is: \[ \boxed{2011} \]

To solve the problem step by step, we need to analyze the function \( f(x) \) and the condition for local maxima at \( x = 2 \). ### Step 1: Define the function The function is given as: \[ f(x) = \begin{cases} 3 - x^2 & \text{if } x \leq 2 \\ ...
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