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The exhaustive set of value of 'a' for which the function `f(x)=a/3(x^3+(a+2)x^2+(a-1)x+2` possess a negative point of minima is `(q,oo)`. The value of q is

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To solve the problem, we will find the values of 'a' for which the function \( f(x) = \frac{a}{3}(x^3 + (a+2)x^2 + (a-1)x + 2) \) has a negative point of minima. We will follow these steps: ### Step 1: Find the first derivative of \( f(x) \) The function is given as: \[ f(x) = \frac{a}{3}(x^3 + (a+2)x^2 + (a-1)x + 2) \] To find the first derivative \( f'(x) \), we differentiate \( f(x) \): \[ f'(x) = \frac{a}{3} \left( 3x^2 + 2(a+2)x + (a-1) \right) \] Simplifying this gives: \[ f'(x) = a \left( x^2 + \frac{2(a+2)}{3}x + \frac{(a-1)}{3} \right) \] ### Step 2: Set the first derivative to zero to find critical points To find the critical points, we set \( f'(x) = 0 \): \[ a \left( x^2 + \frac{2(a+2)}{3}x + \frac{(a-1)}{3} \right) = 0 \] This implies either \( a = 0 \) or: \[ x^2 + \frac{2(a+2)}{3}x + \frac{(a-1)}{3} = 0 \] ### Step 3: Find the second derivative of \( f(x) \) Next, we find the second derivative \( f''(x) \): \[ f''(x) = a \left( 2x + \frac{2(a+2)}{3} \right) \] ### Step 4: Determine conditions for minima For \( f(x) \) to have a minimum at a critical point, we need \( f''(x) > 0 \). Thus: \[ 2ax + 2(a+2) > 0 \] This simplifies to: \[ 2ax + 2a + 4 > 0 \] Dividing by 2 gives: \[ ax + a + 2 > 0 \] Rearranging gives: \[ ax > -a - 2 \] Thus: \[ x > -\frac{a + 2}{a} \quad \text{(for } a \neq 0\text{)} \] ### Step 5: Identify the conditions for a negative point of minima For the point of minima to be negative, we require: \[ -\frac{a + 2}{a} < 0 \] This implies: \[ a + 2 > 0 \quad \text{and} \quad a < 0 \] From \( a + 2 > 0 \), we have: \[ a > -2 \] ### Step 6: Combine the conditions Thus, we have: \[ -2 < a < 0 \] This means the set of values for \( a \) that allow for a negative point of minima is \( (-2, 0) \). ### Conclusion The exhaustive set of values of \( a \) for which the function possesses a negative point of minima is \( (q, \infty) \). From our analysis, we find that \( q = -2 \). ### Final Answer The value of \( q \) is: \[ \boxed{-2} \]
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