The integer k for which the inequality

                       x²-2(4k-1)x+15k²-2k-7>0 is valid for any x is

(A) 2                           (B) 3                              (C) 4            (D) none

d ansewr is B .....

this is an xpression thus b^2-4ac <0

thus u get ...........

(2*(4k-1))^2 - 4(15k^2-2k-7)<0

thus u get .........k^2-6k+8<0

solvin u get (k-2)*(k-4)<0

thus 2<k<4

thus k=3.............

hope it helps..................

               why  D<0?????                 

taht's d condition

if there's an xpression (quadratic) then we always consider that itz discriminant value is always less then 0 .........

if it would have been like this

      x²-2(4k-1)x+15k²-2k-7<0

 then D>0??????

nope.

for an xperssion D is always less then zero

for the ques <0 for all real x, there is no value of k which satisfies so