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

Why Kaysons ?

Video lectures

Access over 500+ hours of video lectures 24*7, covering complete syllabus for JEE preparation.

Online Support

Practice over 30000+ questions starting from basic level to JEE advance level.

Live Doubt Clearing Session

Ask your doubts live everyday Join our live doubt clearing session conducted by our experts.

National Mock Tests

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

Organized Learning

Proper planning to complete syllabus is the key to get a decent rank in JEE.

Test Series/Daily assignments

Give tests to analyze your progress and evaluate where you stand in terms of your JEE preparation.

SPEAK TO COUNSELLOR ? CLICK HERE

Question

 

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

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.    

SIMILAR QUESTIONS

Q1

If f : R  R, (x) is a differentiable bijective function, then which of the following is true?

Q2

If (x) and (x) are two positive and increasing function, then

Q3

If the function y = sin (f (x)) is monotonic for all values of x (where (x) is continuous), then the maximum value of the difference between the maximum and the minimum value of (x), is: 

Q4

 where 0 <x < π then the interval in which g(x) is decreasing is:   

Q5

Find the critical points for f (x) = (x – 2)2/3 (2x + 1).

Q6

 

Find all the values of a for which the function possess critical points.

 

Q7

 

Using calculus, find the order relation between x and tan-1x when x Ïµ [0, ∞). 

Q8

Using calculus, find the order relation between x and tan-1x when  

Q9

The set of all values of ‘b’ for which the function (x) = (b2 – 3b + 2) (cos2x – sin2x) + (b – 1) x + sin 2 does not possesses stationary points is:

Q10

The function  has a local maximum at x =