Get Answers to all your Questions

header-bg qa

please solve rd sharma class 12 chapter 16 Increasing and Decreasing Functions exercise Multiple choice question , question 5 maths textbook solution

Answers (1)

Correct option (a)

Hint: If f(x)  is increasing function {f}'(x)>0

Given:f(x)=2 x^{2}-k x+5

Explanation: It is given that

f(x)=2 x^{2}-k x+5 

Differentiate w.r.t  x

f^{\prime}(x)=2.2 x-k

\because If f(x)  is increasing function {f}'(x)>0

\begin{aligned} &\therefore 4 x-k>0 \text { on }[1,2] \\ &k<4 x \end{aligned}

So, the minimum value of k is 4x

k<4\\ \therefore k\epsilon \left ( -\infty, 4 \right )

Thus k lies in the interval \left ( -\infty ,4 \right )

Posted by

Info Expert 29

View full answer

Crack CUET with india's "Best Teachers"

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