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Let f(x) ={{:(x(x-1)(x-2),(0lexltn),sin(...

Let f(x) =`{{:(x(x-1)(x-2),(0lexltn),sin(pix),(nlexle2n):}`
least value of n for which f(x) has more points of minima than maxima in [0,2n] is _____.

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To solve the problem, we need to analyze the function \( f(x) \) defined in two intervals and determine the least value of \( n \) for which the number of points of minima exceeds the number of points of maxima in the interval \([0, 2n]\). ### Step 1: Define the function The function \( f(x) \) is defined as: - \( f(x) = x(x-1)(x-2) \) for \( 0 \leq x < n \) - \( f(x) = \sin(\pi x) \) for \( n \leq x \leq 2n \) ### Step 2: Analyze the first part of the function For the interval \( [0, n] \): - The function \( f(x) = x(x-1)(x-2) \) is a cubic polynomial. - The critical points can be found by taking the derivative and setting it to zero. **Derivative:** \[ f'(x) = 3x^2 - 6x + 2 \] Setting \( f'(x) = 0 \): \[ 3x^2 - 6x + 2 = 0 \] Using the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{6 \pm \sqrt{(-6)^2 - 4 \cdot 3 \cdot 2}}{2 \cdot 3} = \frac{6 \pm \sqrt{36 - 24}}{6} = \frac{6 \pm \sqrt{12}}{6} = 1 \pm \frac{\sqrt{3}}{3} \] **Critical Points:** - The critical points are \( x = 1 + \frac{\sqrt{3}}{3} \) and \( x = 1 - \frac{\sqrt{3}}{3} \). - We need to evaluate these points to determine if they are minima or maxima using the second derivative test. ### Step 3: Analyze the second derivative **Second Derivative:** \[ f''(x) = 6x - 6 \] Evaluate \( f''(x) \) at the critical points: - For \( x = 1 + \frac{\sqrt{3}}{3} \): \[ f''(1 + \frac{\sqrt{3}}{3}) = 6(1 + \frac{\sqrt{3}}{3}) - 6 = 2\sqrt{3} > 0 \quad (\text{minima}) \] - For \( x = 1 - \frac{\sqrt{3}}{3} \): \[ f''(1 - \frac{\sqrt{3}}{3}) = 6(1 - \frac{\sqrt{3}}{3}) - 6 = -2\sqrt{3} < 0 \quad (\text{maxima}) \] ### Step 4: Count extrema in the interval [0, n] In the interval \( [0, n] \): - There is 1 point of minima and 1 point of maxima. ### Step 5: Analyze the second part of the function For the interval \( [n, 2n] \): - The function \( f(x) = \sin(\pi x) \) oscillates and has maxima and minima at regular intervals. - The number of maxima and minima in this interval can be calculated as follows: - The function \( \sin(\pi x) \) has 1 maximum and 1 minimum in each interval of length 2. ### Step 6: Count extrema in the interval [n, 2n] - In the interval \( [n, 2n] \), there are \( n \) points of maxima and \( n \) points of minima. ### Step 7: Total counts of minima and maxima - Total minima in \( [0, 2n] \): \( 1 + n \) - Total maxima in \( [0, 2n] \): \( 1 + n \) ### Step 8: Finding the least value of n To find the least value of \( n \) for which the number of minima exceeds the number of maxima: \[ 1 + n > 1 + n \quad \text{(not possible)} \] We need to check higher values of \( n \): - For \( n = 1 \): Minima = 1, Maxima = 1 (equal) - For \( n = 2 \): Minima = 2, Maxima = 2 (equal) - For \( n = 3 \): Minima = 3, Maxima = 2 (minima > maxima) ### Conclusion The least value of \( n \) for which the number of points of minima is greater than the number of points of maxima in the interval \([0, 2n]\) is: \[ \boxed{3} \]

To solve the problem, we need to analyze the function \( f(x) \) defined in two intervals and determine the least value of \( n \) for which the number of points of minima exceeds the number of points of maxima in the interval \([0, 2n]\). ### Step 1: Define the function The function \( f(x) \) is defined as: - \( f(x) = x(x-1)(x-2) \) for \( 0 \leq x < n \) - \( f(x) = \sin(\pi x) \) for \( n \leq x \leq 2n \) ### Step 2: Analyze the first part of the function ...
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CENGAGE ENGLISH-MONOTONICITY AND MAXIMA MINIMA OF FUNCTIONS-Numerical Value Type
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  14. Let f(x) ={{:(x(x-1)(x-2),(0lexltn),sin(pix),(nlexle2n):} least valu...

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