Q.

 The curve y=f(x) which satisfies the condition f'(x)>0 and f''(x)<0 for all real x, is

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

a

 

 

Question Image

b

 

Question Image

 

c

 

Question Image

d

 

 

Question Image

answer is D.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Given: f'(x)>0 and f''(x)<0 for all real x.

To find: Curve y=f(x) which satisfy given conditions.

Step-1

Choose x1,x2 such that x2>x1and fx2>fx1,

example: 

Question Image

                                                                                                                                OR

Question Image

 

which means that function is increasing in interval x1,x2.

Step-2

Consider, f'(x)>0 then function is strictly increasing in its domain. 

Hence, option 1 , 2are ruled out since they both decrease at some interval. 

Question Image

As it can be observed that the slope of the curve is not strictly increasing it is increasing in some interval and decreasing in other intervals same is the case for option-2 as , In option-2

Question Image

As it can easily seen in the graph that fx is strictly decreasing because its slope is always negative.

Now , f''(x)<0 xD then graph of f(x) is concave downward like,

Question Image

Thus curve y=f(x) that satisfies the condition f'(x)>0,f''(x)<0xR is concave downward . 

Hence option-4 is the correct answer.

Watch 3-min video & get full concept clarity
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon