#1: -1 is not a solution of x³=1, since (-1)³=-1≠1
#2: This has three solutions: 1, (-1+i√3)/2, and (-1-i√3)/2. You may verify this by simple multiplication.
2006-10-14 08:26:12
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answer #1
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answered by Pascal 7
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you are asking for cube roots of 1
if you know trigonometry use this equation
x^1/n = x^1/n(cos(2*k*pi/n)+i sin(2*k*pi/n))
x^1/n is the root you are looking for on the left side
on the right side it is the main root, in your example it was 1.
pi=3.14159.....
n=root you are finding, in you example it was 3
k=any number less than k
so for x= 1 and n=3, substitue 0 ,1 and 2 in the equation for k,
when it is 0: cos 2*0*pi/n=1 +i sin 2*0*k/n=0 and so the answer is
1(1+0) or just 1
im too lazy to do the math for k=1 and k=2
2006-10-14 15:43:03
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answer #2
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answered by locomexican89 3
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Only solution is "1". "-1" isn't valid since x^3 will equal -1 when x=-1.
2006-10-14 15:56:43
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answer #3
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answered by ViCKi!™|` 5
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No. If you substituted i or -i for x you wouldn't get 1 for a solution.
-1 isn't a solution either because (-1)^3 = -1.
2006-10-14 15:13:21
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answer #4
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answered by PatsyBee 4
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x^3 = 1 has only solution, x=1, with multiplicity of 3
(if you don't know what multiplicity means, don't worry about it. bottom line is the only answer, even including the complex numbers, is x=1 for this equation)
2006-10-14 15:10:34
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answer #5
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answered by I ♥ AUG 6
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x^3 = 1 has 3 solutions... in polar notation (radius,theta) they are (1,0) (1, 2pi/3) (1, 4pi/3).
-1 is not a solution.
2006-10-14 15:23:23
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answer #6
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answered by Jay 3
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x^3 - 1 = 0
(x-1)(x^2 + x + 1) = 0
x = (1, (-1+sqrt(-3))/2, (-1-sqrt(-3))/2)
2006-10-14 15:41:05
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answer #7
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answered by Helmut 7
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NO.
2006-10-14 15:11:41
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answer #8
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answered by Anonymous
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