i^(4n+2) = (i^4n)(i^2)
since i^4n = 1 for all whole number values of n, you get
(1)(i^2) = -1
The answer is negative one.
i^1 = sqrt(-1) = i
i^2 = (-1) = -1
i^3 = (-1)sqrt(-1) = -i
i^4 = (-1)(-1) = 1
Then the process repeats
i^5 = (i^4)(i) = (1)(i) = i
i^6 = (i^4)(i^2) = (1)(-1) = -1 ...
2006-11-29 12:28:06
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answer #1
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answered by Nicknamr 3
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If n = 0
i^(4n+2)
i^[4(0) + 2]
i^(0 + 2)
i^2
REMEMBER: i^2 = -1
Substitute -1 for i^2
( -1 )
1( -1)
-1
i^2= -1
Therefore when n= 0, the answer will be -1.
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If n = a POSITIVE odd number
For example, n=1,3,5,7,etc.
i^(4n+2)
i^[4(1) + 2]
i^(4 + 2)
i^6
(i^2)^3
REMEMBER: i^2 = -1
Substitute -1 for i^2
( -1 )^3
i^6 = -1
Therefore when n= a POSITIVE odd #, the answer will, ALSO, be -1.
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If n = an POSITIVE even number
For example, n=2,4,6,8,etc.
i^(4n+2)
i^[4(2) + 2]
i^(8 + 2)
i^10
(i^2)^5
REMEMBER: i^2 = -1
Substitute -1 for i^2
( -1 )^5
i^10 = -1
Therefore when n= an even #, the answer will be, once more,-1.
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If n = an NEGATIVE odd number
For example, n= -1,-3,-5,etc.
i^(4n+2)
i^[4(-1) + 2]
i^(-4 + 2)
i^(-2)
(i^2)^(-1)
REMEMBER: i^2 = -1
Substitute -1 for i^2
( -1 )^(-1)
(-1/1)^(-1)
(1/-1)^(1)
(-1)^1
-1
Therefore, when n= NEGATIVE odd #, again, the answer is -1.
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If n = an NEGATIVE even number
For example, n= -2,-4,-6,-8,etc.
i^(4n+2)
i^[4(-2) + 2]
i^(-8 + 2)
i^(-6)
(i^6)^(-1)
[(i^2)^3]^(-1)
REMEMBER: i^2 = -1
Substitute -1 for i^2
[( -1 )^ 3]^(-1)
(-1)^(-1)
(-1/1)^(-1)
(1/-1)^(1)
(-1)^1
-1
Therefore, when n= NEGATIVE even # -- YES, you guessed it: the answer is -1.
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CONCLUTION:
Regardless if n = an odd or an even number, POSITIVE or NEGATIVE or zero, the result will will ALWAYS be -1.
2006-11-29 23:36:47
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answer #2
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answered by LovesMath 3
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