Q.

Let k and m be positive real number such that the function f(x)=3x2+kx+1,    0<x<1mx2+k2          , x1
is differentiable for all x > 0. Then 8f(8)f18 is equal to

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

answer is 309.

(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

detailed_solution_thumbnail

f(x)=3x2+kx+13mx2+k2
 For continuity at x=1
f1=f1+ 3+k2=m+k2
f(x)x=1=6x+k2x+1x=1=6+k22f(x)x=1+=2mxx=1+=2m
 For differentiability at x=1
6+k22=2m
k=742 and m=10332
f(8)=2mxx=8=16m=1032f18=6x+k2x+1x=18=438f(8)f18=309

Watch 3-min video & get full concept clarity
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

whats app icon