Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • Please solve RD Sharma class 12 Chapter Maxima and Minima exercise Multiple choice question, question 5 maths textbook solution.

Please solve RD Sharma class 12 Chapter Maxima and Minima exercise Multiple choice question, question 5 maths textbook solution.

Answers (1)

Answer: Option (b) a minimum at x = 1  

Hint: For local maxima or minima, we must have f'(x) =0 .

Given: f(x)=x^3+3x^2-9x+2

Solution:

We have,

f(x)=x^3+3x^2-9x+2

f'(x)=3x^2+6x-9

For maxima and minima f'(x)=0

\Rightarrow 3x^2+6x-9=0

\Rightarrow x^2+2x-3=0

\Rightarrow (x+3)(x-1)=0

\Rightarrow x=-3,1

Now,

f''(x)=6x+6

f''(1)=12>0

So, x =1 is a point of local minima.

Also, f''(-3)=-18 +6=-12<0

So, x = -3 is a point of local maxima.

Posted by

infoexpert24

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

CBSE Class 10, 12 compartment 2024 exams today for 2.5 lakh students; exam timings, guidelines
anam-khan

CBSE compartment admit card 2024 out at cbse.gov.in; exams from July 15
anam-khan

Reports saying CBSE cannot conduct board exams twice a year currently ‘totally incorrect’; board denies claims

Latest Question