Q. 6 D4.1( 16 Votes )
Find the interval
Answer :
It is given that function f(x) = 6 – 9x – x2
f’(x) = -9 – 2x
If f’(x) = 0, then we get,
⇒ x =
So, the point x = divides the real line into two disjoint intervals,
So, in interval
f’(x) = -9 – 2x > 0
Therefore, the given function (f) is strictly increasing for x < .
And in interval
f’(x) = -9 – 2x < 0
Therefore, the given function (f) is strictly decreasing for x>.
Thus, f is strictly decreasing for x>.
Rate this question :
How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
view all courses
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation


RELATED QUESTIONS :
Find the interval
RD Sharma - Volume 1Find the interval
RD Sharma - Volume 1Find the interval
RD Sharma - Volume 1Find the interval
RD Sharma - Volume 1Find the interval
RD Sharma - Volume 1Find the interval
RD Sharma - Volume 1Show that the alt
Mathematics - Board PapersFind the interval
RD Sharma - Volume 1Find the interval
RD Sharma - Volume 1Find the interval
RD Sharma - Volume 1