roots - exponents - absolutes
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I would go with C)
I am asuming = sign is missing in the diagram
sqrt(|x|) ^ 2 is |x| which is x if x is positive or 0
Stmt II
x^0 = 1
x can be positive or negative
INSUFF
Toegther x has to be psoitive since 0^0 is not equal to 1
I am asuming = sign is missing in the diagram
sqrt(|x|) ^ 2 is |x| which is x if x is positive or 0
Stmt II
x^0 = 1
x can be positive or negative
INSUFF
Toegther x has to be psoitive since 0^0 is not equal to 1
Last edited by cramya on Sun Dec 28, 2008 3:16 pm, edited 1 time in total.
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Statement I
(sqrtlxl)^2 = x
if x = -1
lxl = 1
(sqrt 1)^2 = 1 but this is not equal to x, which is -1
Hence only way this could be possible when x = positive.
Sufficient
Statement II
x^0 = 1
irrespective of any value of x, any value when raised to the power of 0 will always result in 1, Therefore x could be positive or negative.
Insufficient.
Hence A.
(sqrtlxl)^2 = x
if x = -1
lxl = 1
(sqrt 1)^2 = 1 but this is not equal to x, which is -1
Hence only way this could be possible when x = positive.
Sufficient
Statement II
x^0 = 1
irrespective of any value of x, any value when raised to the power of 0 will always result in 1, Therefore x could be positive or negative.
Insufficient.
Hence A.
No rest for the Wicked....
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Nice work cramya, missed that 0, I hate to make silly mistakes.cramya wrote:PC I thought of A too initially then decided C) for reasons posted above.
Let me know what u think
Answer should be C.
I also have a doubt in statement II
-2^0 = -1
2^0 = 1
are these correct or is it I am right in my logic to assume that any number positive or negative, when raised to the power of 0 is 1.
thanks.
No rest for the Wicked....
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(1) x can be positive or zero --> insuff
(2) x can be any number EXCEPT zero (0^0 is undefined)
(1) and (2) combine to tell us that x must be positive.
Answer: C
(2) x can be any number EXCEPT zero (0^0 is undefined)
(1) and (2) combine to tell us that x must be positive.
Answer: C
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I also have a doubt in statement II
-2^0 = -1
2^0 = 1
are these correct or is it I am right in my logic to assume that any number positive or negative, when raised to the power of 0 is 1
PC its always 1.
-2^0 = 1
2^0 = 1
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Thanks Buddy.cramya wrote:I also have a doubt in statement II
-2^0 = -1
2^0 = 1
are these correct or is it I am right in my logic to assume that any number positive or negative, when raised to the power of 0 is 1
PC its always 1.
-2^0 = 1
2^0 = 1
No rest for the Wicked....
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pls tell me ...cramya...howcm u arrvied it on...pls elaborate...
i face too much prob in absolute values.
pls elaborate ur sol.
i face too much prob in absolute values.
pls elaborate ur sol.
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cramya wrote:
sqrt(|x|) ^ 2 is |x| which is x if x is positive or 0
This is creating probs. as u said , sqrt(|x|) ^ 2 is |x|
now it boils down to |x| =x
now if x is +ve it holds
if x is -ve, then LHS = x and RHS = -x , not equal....
why and hw u hv taken 0 in consideration is my ques.
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Hi Vivek,why and hw u hv taken 0 in consideration is my ques
Basic but important piece of information:
The absolute value(never negative) or magnitude of a real number x is denoted
by |x| and is defined by
|x| = x if x ≥ 0 ( x is greater than or equal to 0)
|x| = −x if a < 0
stmt I tells us it either a 0 or a positive number. Hence INSUFF
Together it cant be 0 since 0^0 is undefined so has to be a positive number
Hope this helps!