" With usual notations,"3c_(4)+5c_(1)+7c_(2)+.....+(2n+3)c_(n)=

3C_(0)+5C_(1)+7C_(2)++(2n+3)C_(n)=2^(n)(n+3)

C_(1) + 4.C_(2) + 7.C_(3) +......+(3n - 2).C_(n) =

C_(1)+4.C_(2)+=7.C_(3)+......+(3n-2).C_(n)=

If (1+x)^(n)= C_(0)+C_(1).x+C_(2). x^(2)+.. . C_(n). x^(n) in the usual notation then C_(0)^(2)+C_(1)^(2)+C_(2)^(2)+.. .+C_(n)^(2) =

In triangleABC , with usual notations b=2c and B=3C, then sinA=