if Σ of r=1 to n of U_a is equal to 3n^2+2n , find U_a. Hence find Σ of r=n+1 to 2n of U_a Ans: 6r-1 , 9n^2+2n
and also find sum of: Σ of r=n to 2n of r(2r+3) ans1/6)n(28n^2+57n+29)
: Σ of r=1 to 3n of r(r^2+1) ans3/4)n(3n+1)(9n^2+3n+2)
if Σ of r=1 to n of U_a is equal to 3n^2+2n , find U_a. Hence find Σ of r=n+1 to 2n of U_a Ans: 6r-1 , 9n^2+2n
and also find sum of: Σ of r=n to 2n of r(2r+3) ans1/6)n(28n^2+57n+29)
: Σ of r=1 to 3n of r(r^2+1) ans3/4)n(3n+1)(9n^2+3n+2)