What is summition of k is to the powr 2 28Ck where value of k lies from 0 to 28

(1+x)^28=28C0+28C1*x+28C2*x^2---------------------------28C28*x^28
differentiate we get
28*(1+x)^27=28C1*1+28C2*2*x---------------------------28C28*28*x^27
multiply x on both sides
28*(1+x)^27*x=28C1*x+28C2*2*x^2---------------------------28C28*28*x^28
Again differentiate we get
28C1*1+28C2*2*2*x---------------------------28C28*28*28*x^27
put x=1
=k*k*28Ck ( k lies from 1 to 28) (for k=0,k^2=0)
so summation of k from 0 to 28=differentiation of (28*(1+x)^27*x)
=28*(1+x)^26*(28*x+1)
and put x=1
=28*29*2^26
so answer is 203*2^28
10 years agoHelpfull: Yes(3) No(4)
according to formula
summation X^(NCP) where P=0,1,2,3......n=(X+1)^N
so ans will be (2+1)^28(n here is 28)=3^28
10 years agoHelpfull: Yes(3) No(4)
please expalin it
9 years agoHelpfull: Yes(0) No(1)
explain any one how to solve this question??
9 years agoHelpfull: Yes(0) No(0)

. What is summition of ( k is to the powr 2 * 28Ck ) where value of k lies from 0 to 28.