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The sum of the series 1 2 ! - 1 3 ! + 1 4 ! - upto infinity is

Options

  1. Ae⁻²
  2. Be⁻¹
  3. Ce ^ -1 / 2
  4. De ^ 1 / 2

Correct answer

B. e⁻¹

Step-by-step solution

e^ -x =1-x+ x^2 2 ! - x^3 3 ! + x^4 4 ! - put x=1 1 2 ! - 1 3 ! + 1 4 ! =e⁻¹ .

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