3- – Tinku Tara

Question Number 109954 by Study last updated on 26/Aug/20

! 3 = ? ? ? ?

Answered by mathdave last updated on 26/Aug/20

s o l u t i o n

r e c a l l t h a t

! x = x! \underset{n = 0}{\sum^{x}} \frac{{(- 1)}^{n}}{n!}

! 3 = 3! \underset{n = 0}{\sum^{3}} \frac{{(- 1)}^{n}}{n!} = 6 (\frac{{(- 1)}^{0}}{0!} + \frac{{(- 1)}^{1}}{1!} + \frac{{(- 1)}^{2}}{2!} + \frac{{(- 1)}^{3}}{3!})

! 3 = 6 (1 - 1 + \frac{1}{2} - \frac{1}{6}) = 6 (\frac{3 - 1}{6}) = 2

∵! 3 = 2 t h i s m e a n t h a t t h e h o w m a n y w a y 3

o b j e c t c a n b e d i s a r r a n g e i s 2 w a y s

Commented by mathdave last updated on 26/Aug/20

i m e a n t h a t 3

o b j e c t c a n b e

d i s a r r a g e i n

2 w a y s

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