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absolute values

by pink_08 » Fri Mar 12, 2010 11:35 pm
I saw this property in one of the DS questions -

x=-3y This tells us X and Y have different signs. ( -,+)

we can also say |x| = 3|y|


Which number property does the above reflect ? Are n't we forgetting the negative sign by converting to absolute value ?

Pls clarify
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by Phirozz » Sat Mar 13, 2010 12:24 am
pink_08 wrote:I saw this property in one of the DS questions -

x=-3y This tells us X and Y have different signs. ( -,+)

we can also say |x| = 3|y|


Which number property does the above reflect ? Are n't we forgetting the negative sign by converting to absolute value ?

Pls clarify
After converting both sides are +ve. So it does not matter whether sign of x and y are +ve or -ve. We are concerned about onl absolute values
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by pink_08 » Sat Mar 13, 2010 8:31 pm
Can you please explain in detail. I'm still missing a few pieces here.
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by sarthak » Mon Mar 15, 2010 9:51 pm
this |number| is known as mod . If you use this operand it means strip off the sign and just be concerned about the absolute value.

eq. x=3 y= -3

so x is not equal to y

but x =|y| because thier absolute values is 3 is same .

I hope you are clear now. In case of further doubt pls lemme kno
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by kevincanspain » Tue Mar 16, 2010 2:35 am
pink_08 wrote:I saw this property in one of the DS questions -

x=-3y This tells us X and Y have different signs. ( -,+)

we can also say |x| = 3|y|


Which number property does the above reflect ? Are n't we forgetting the negative sign by converting to absolute value ?

Pls clarify

Remember that if two numbers are equal, their absolute values (distances from zero) are equal. (The reserve, however, is not always true)

The absolute value of a product of two terms is the product of the absolute values of the two terms.
In short, |ab| =|a| |b|

Thus |-3y| = |-3| |y| = 3|y|
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