Question 5  CBSE Class 12 Sample Paper for 2022 Boards (MCQ Based  for Term 1)  Solutions of Sample Papers and Past Year Papers  for Class 12 Boards
Last updated at April 16, 2024 by Teachoo
Find the intervals in which the function f given by
f
(x) = x2 – 4x + 6 is strictly increasing:
(a) (∞, 2) ∪ (2,∞) (b) (2,∞)
(c) (∞, 2) (d) (∞, 2] ∪ (2,∞)
This question is
inspired from

Example 10
 Chapter 6 Class 12 Application of Derivatives
Transcript
Question 5 Find the intervals in which the function f given by f (x) = x2 – 4x + 6 is strictly increasing: (a) (−∞, 2) ∪ (2,∞) (b) (2,∞) (c) (−∞, 2) (d) (−∞, 2] ∪ (2,∞)
f(𝑥) = 𝑥2 – 4𝑥 + 6
Calculate f’(𝒙)
𝑓’ (𝑥) = 2𝑥 – 4
Calculate f’(𝒙) = 0
2𝑥 – 4 = 0
2𝑥 = 4
𝑥 = 4/2=2
Hence 𝑥 = 2 divide real line into 2 disjoint intervals.
Plotting points on number line
Hence.
f is strictly increasing in interval (2 , ∞)
So, the correct answer is (b)
Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.
Hi, it looks like you're using AdBlock :(
Displaying ads are our only source of revenue. To help Teachoo create more content, and view the adfree version of Teachooo... please purchase Teachoo Black subscription.
Please login to view more pages. It's free :)
Teachoo gives you a better experience when you're logged in. Please login :)
Solve all your doubts with Teachoo Black!
Teachoo answers all your questions if you are a Black user!