Maxima and MinimaHard
Question
Suppose the cube x3 - px + q has three distinct real roots where p > 0 and q > 0. Then which one of the following holds?
Options
A.The cubic has minima at
and maxima at 
and maxima at 
B.The cubic has minima at
and maxima at 
and maxima at 
C.The cubic has minima at both
and 
and 
D.The cubic has maxima at both
and 
and 
Solution

Let f(x) = x3 - px + q
Now for maxima/minima
f′(x) = 0
⇒ 3x2 - p = 0
⇒ x2 =

∴ x = ±

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