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If maximum value of f(x)=2x3+3x2−6ax+10f(x) = 2x^3 + 3x^2 - 6ax + 10 occurs at x=−3x = -3, then the value of α\alpha is ____

Solution

✅ Correct Option: 3

When a function has a maximum at a point, the first derivative equals zero at that point.

Given: f(x)=2x3+3x2−6αx+10f(x) = 2x^3 + 3x^2 - 6\alpha x + 10

Finding the first derivative using the power rule:

f′(x)=6x2+6x−6αf'(x) = 6x^2 + 6x - 6\alpha


Since the maximum occurs at x=−3x = -3:

f′(−3)=0f'(-3) = 0

Substituting x=−3x = -3:

6(−3)2+6(−3)−6α=06(-3)^2 + 6(-3) - 6\alpha = 0

6(9)−18−6α=06(9) - 18 - 6\alpha = 0

54−18−6α=054 - 18 - 6\alpha = 0

36−6α=036 - 6\alpha = 0

6α=366\alpha = 36

α=6\alpha = 6


Therefore, α=6\alpha = 6

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