AP EAMCET2001MathematicsSequences and Series
2 2 ! + 2+4 3 ! + 2+4+6 4 ! + is equal to
Options
- Ae
- Be⁻¹
- Ce⁻²
- De⁻³
Correct answer
A. e
Step-by-step solution
We have, aligned T_n & = 2+4+6+ +2 n (n+1) ! T_n & = 2 n (n+1) ! = 2 n(n+1) 3 (n+1) n(n-1) ! & = 1 (n-1) ! aligned aligned S & =T₁+T₂+T₃+ & =1+1+ 1 2 ! + 1 3 ! + =e aligned