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why is 1/i = -i, I don't understand how it's -i

can someone explain to me why 1/i = -i

thanks

2007-11-11 21:30:21 · 4 answers · asked by Anonymous in Science & Mathematics Mathematics

4 answers

By definition i² = - 1
1/i = i / i² = i / (-1) = - i

2007-11-12 03:47:05 · answer #1 · answered by Como 7 · 2 2

Its an imaginary number... what do you expect? Magic happens in the imagination.


i = √[ -1 ]

1 / i = 1 / √[ -1 ]

Simplify that, since we hate radicals in the denominator
1 / i = ( 1 / √[ -1 ] ) ⋅ ( i / i )
1 / i = ( 1 / √[ -1 ] ) ⋅ ( √[ -1 ]/√[ -1 ] )
1 / i = 1 · √[ -1 ] / √[ -1 ] · √[ -1 ]
1 / i = √[ -1 ] / -1
1 / i = i / -1 = -i

2007-11-12 05:37:03 · answer #2 · answered by Anonymous · 0 1

i = sq rt (-1)
if you have 1/i and multiply it by i/i. You get i/i^2, which is i/(-1)
or -i.

2007-11-12 05:39:50 · answer #3 · answered by Anonymous · 1 1

because i^2=-1

that means -i^2=1

if you divide by i you get... what?

2007-11-12 05:34:49 · answer #4 · answered by Theta40 7 · 0 1

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