isi 2009

[seema]

If f(x) is a real valued function such that 2f(x)+3f(-x)= 55-7x , for every x belongs to R. then f(3)=
a.  40
b.  32
c.  26
d.  10

[seema]

Q14.  lim (n tends to infinity) (1^2+2^2+....+n^2)/n^3 equals
a.  0
b.  1/3
c.  1/6
d.  1

i am getting the answer as 0.?

[sunny2009]

question number 14
lim (n tends to infinity) (1^2+2^2+....+n^2)/n^3
                       implies {n(n+1)(2n+1)}/6n^3
                      implies 2n^2+3n+1/6n^2
                      implies 1/3+1/2n+1/6n^2
                      implies 1/3   (when n tends to infinity)
 so answer should be 1/3 in my opinion.

[lovekesh]

For the first question
put x= -x
u will get second equation. cancel out f(-x) term be manipulation. U will get relation in f(x). Then solve it. I got 32.

[seema]

thanx...both of u..:)