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f(x) = |x|+|x-1| +|x-2|, then which one ...

`f(x) = |x|+|x-1| +|x-2|`, then which one of the following is not correct ?

A

f(x) has a minimum at x=1

B

f(x) has a maximum at x=0

C

f(x) has niether a maximum nor a minimum at x=0

D

f(x) has niether a maximum nor a minimum x=2

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The correct Answer is:
To solve the problem \( f(x) = |x| + |x-1| + |x-2| \) and determine which statement is not correct, we will analyze the function step by step. ### Step 1: Identify the critical points The absolute value function changes at the points where the expression inside the absolute value equals zero. For \( f(x) \), the critical points are: - \( x = 0 \) (where \( |x| \) changes) - \( x = 1 \) (where \( |x-1| \) changes) - \( x = 2 \) (where \( |x-2| \) changes) ### Step 2: Analyze the function in different intervals We will analyze \( f(x) \) in the intervals determined by the critical points: 1. \( x < 0 \) 2. \( 0 \leq x < 1 \) 3. \( 1 \leq x < 2 \) 4. \( x \geq 2 \) #### Interval 1: \( x < 0 \) In this interval, all terms are negative: \[ f(x) = -x + (1 - x) + (2 - x) = 3 - 3x \] #### Interval 2: \( 0 \leq x < 1 \) In this interval, \( |x| \) is positive while the other two terms are still positive: \[ f(x) = x + (1 - x) + (2 - x) = 3 - x \] #### Interval 3: \( 1 \leq x < 2 \) In this interval, \( |x| \) and \( |x-1| \) are positive while \( |x-2| \) is negative: \[ f(x) = x + (x - 1) + (2 - x) = x + 1 \] #### Interval 4: \( x \geq 2 \) In this interval, all terms are positive: \[ f(x) = x + (x - 1) + (x - 2) = 3x - 3 \] ### Step 3: Determine the values at critical points Now we will find the values of \( f(x) \) at the critical points: - At \( x = 0 \): \[ f(0) = |0| + |0-1| + |0-2| = 0 + 1 + 2 = 3 \] - At \( x = 1 \): \[ f(1) = |1| + |1-1| + |1-2| = 1 + 0 + 1 = 2 \] - At \( x = 2 \): \[ f(2) = |2| + |2-1| + |2-2| = 2 + 1 + 0 = 3 \] ### Step 4: Analyze the behavior of \( f(x) \) - For \( x < 0 \), \( f(x) = 3 - 3x \) is increasing. - For \( 0 \leq x < 1 \), \( f(x) = 3 - x \) is decreasing. - For \( 1 \leq x < 2 \), \( f(x) = x + 1 \) is increasing. - For \( x \geq 2 \), \( f(x) = 3x - 3 \) is increasing. ### Step 5: Identify minimum and maximum points - The minimum value occurs at \( x = 1 \) where \( f(1) = 2 \). - The function does not have a maximum value since it increases indefinitely for \( x \geq 2 \). ### Conclusion From the analysis: - \( f(x) \) has a minimum at \( x = 1 \). - \( f(x) \) does not have a maximum value. - At \( x = 2 \), it neither has a maximum nor a minimum. ### Final Answer The statement that is not correct is: "f(x) has a maximum at \( x = 0 \)".
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