﻿   Find the local maximum and local minimum of f (x) = x3 + 3x in [–2, 4]. : Kaysons Education

# Find The Local Maximum And Local Minimum Of f (x) = x3 + 3x in [–2, 4].

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## Question

### Solution

Correct option is

Minimum = –14 & Maximum = 76

Given,                  (x) = x3 + 3x

which is strictly increasing for all x Ïµ R and thus, increasing for [–2, 4].

Hence, local minimum is (–2) = (–2)3 + 3(–2) = –14

and local maximum is f (4) = (4)3 + 3(4) = 76.

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