Maxima and MinimaHard
Question
If the point of minima of the function, f(x) = 1+ a2x - x3 satisfy the inequality 
< 0, then ′a′ must lie in the interval :
< 0, then ′a′ must lie in the interval :Options
A.(-3 √3, 3√3)
B.(-2√3, -3√3)
C.(2√3, 3√3)
D.(-3√3, -2√3) ∪ (2√3, 3√3)
Solution
The solution set of the inequality
< 0 ⇒ -3 < x < -2
f(x) = 1 + a2x - x3
f′(x) = a2 - 3x2
= (a - √3 x)(a + √3 x)
If a > 0 -3 <
< -2
If a < 0 -3 <
< - 2(-2√3, -3√3)
< 0 ⇒ -3 < x < -2f(x) = 1 + a2x - x3
f′(x) = a2 - 3x2
= (a - √3 x)(a + √3 x)
If a > 0 -3 <
< -2If a < 0 -3 <
< - 2(-2√3, -3√3)Create a free account to view solution
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