`1+2+3+….+n=(n(n+1))/2`

By the principle of mathematical induction prove that 1+2+3+4+…n= (n(n+1))/2

Prove by mathematical induction that 1^3+2^3+……+n^3=[(n(n+1))/2]^2

Using mathematical induction, prove that (1)/(1.3.5) + (2)/(3.5.7) +….+(n)/((2n-1)( 2n+1) ( 2n+3)) =( n(n+1))/( 2(2n+1) (2n+3))

Sum of series : 1+2+3+......... +n is (A) ((n)(n+1))/2 (B) n(n+1) (C) ((n+1)(n+2))/2 (D) none of these.

1+2+3+…….+(n+1)= ((n+1) (n+2))/(2) , n in N .

1^2/(1.3)+2^2/(3.5)+3^2/(5.7)+.....+n^2/((2n-1)(2n+1))=((n)(n+1))/((2(2n+1))

(1^(2))/(1.3)+(2^(2))/(3.5)+(3^(2))/(5.7)+.....+(n^(2))/ ((2n-1)(2n+1))=((n)(n+1))/((2(2n+1)))

Prove that 1^2/(1.3)+2^2/(3.5)+3^2/(5.7)+.....+n^2/((2n-1)(2n+1))=((n)(n+1))/((2(2n+1))

1^2/(1.3)+2^2/(3.5)+3^2/(5.7)+.....+n^2/((2n-1)(2n+1))=((n)(n+1))/((2(2n+1))