BITSAT2020MathematicsSequences and SeriesActual
The sum of the infinite series 2² 2 ! + 2⁴ 4 ! + 2⁶ 6 ! + is equal to
Options
- Ae ²+1 2 e
- Be ⁴+1 2 e ²
- C( e ²-1 )² 2 e ²
- D( e ²+1 )² 2 e ²
Correct answer
C. ( e ²-1 )² 2 e ²
Step-by-step solution
We know that e^ x +e^ -x 2 =1+ x² 2 ! + x⁴ 4 ! + x⁶ 6 ! + keeping x =2 , we get Expression = 1 2 [ e²+e⁻² 2 ]-1= (e²-1 )² 2 e²