PROBLEM 1:
- √(-25)
- √(25)(-1)
- [ √(25) * √(-1) ]
- [ 5 * i ]
Answer:
-5i
PROBLEM 2:
(- √(-25))²
You already know that the part inside the parentheses is -5i
(-5i)²
= (-5)²(i)²
= 25 x -1
Answer:
-25
You can also solve this just by thinking logically. You have the square of a negative number. This is the same as the square of the positive number:
(-√-25)² --> (√-25)²
And the square of a square root is just the number itself.
Answer:
-25
2007-11-27 11:57:33
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answer #1
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answered by Puzzling 7
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The square root of a negative number gives you the imaginary number i with the root.
1) sqrt(25) = 5. So, sqrt(-25)=5i.
Therefore, -sqrt(-25)=-5i
2) Take your answer from #1 (-5i) and square it:
(-5i)^2=25i^2
i^2=-1, so 25i^2=25(-1)
=-25
2007-11-27 11:56:42
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answer #2
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answered by Amelia 6
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you need to know about complex numbers for this
1) sqrt ( - 25 ) = sqrt (-1 * 25 ) = 5 * sqrt (-1)
In complex numbers one writes sqrt (-1) as i [ or j if you are an electrical engineer ] so
- sqrt ( -25 ) = -5 i
2) ( -5 i )^2 = (-5)^2 * (i)^2 = 25 * (-1) = - 25
2007-11-27 12:02:09
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answer #3
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answered by lienad14 6
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Radicals can be factored:
-â(-25) = -â(25)â(-1)
= -5â(-1)
= -5i
(-â-25)² = (â-25)²
= [â((-1)(25))]²
= [â(-1)â(25)]²
= [â(-1)]² [â(25)]²
= [i]² [5]²
= -25
2007-11-27 12:12:19
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answer #4
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answered by DWRead 7
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[06]
1)-sqrt(-25)
= - sqrt(25*-1)
= -sqrt(25*i^2)
=-5i
=
2)(-sqrt(-25)^2
=(-5i)^2
=25i^2
=-25
2007-11-27 11:59:31
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answer #5
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answered by alpha 7
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-5i
-5
2007-11-27 11:55:17
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answer #6
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answered by lvscottt 1
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