The Total solution for NCERT class 6-12
1 × 2 × 3 + 2 × 3 × 4 + 3 × 4 × 5 + …
Given series is 1 × 2× 3 + 2 × 3 × 4 + 3 × 4 × 5 + …
It’s seen that,
nth term, an = n ( n +1) ( n + 2)
= (n2 + n)(n + 2)
= n3 +3n2 + 2n
Then, the sum of nterms of the series can be expressed as