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POLL: A simple mathematical problerm
 
forty-two  posted on Apr 28, 2011 4:19:09 PM - Report post

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quote:
originally posted by Neo7

Back to this again.

I asked my mathematics professor (Ph.D. in mathematics). He says the answer is 288 becaues the divisor of the division problem is always the length of one real number unless specificed by a sub-equation completely encased in parenthesis/brackets (with the open parenthesis/bracket occuring immediately after the division symbol).

48/2(3+9) = 288
48/[2(3+9)] = 2

So what does 48/i2 come out to? 24i or -24i? I know that it's improper to write the i first, but we've clearly thrown syntax out the window.

 
Neo7  posted on Apr 28, 2011 5:42:16 PM - Report post

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Rewrite the i as Math.Sqrt(-1) and rationalise the denominator. It will return negative.

1. 48/(2i)
2. (48i)/(2 * -1)
3. (48i) / (-2)
4. -24i

 
forty-two  posted on Apr 28, 2011 5:44:15 PM - Report post

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quote:
originally posted by Neo7

Rewrite the i as Math.Sqrt(-1) and rationalise the denominator. It will return negative.

1. 48/(2i)
2. (48i)/(2 * -1)
3. (48i) / (-2)
4. -24i

But like you said, "the divisor of the division problem is always the length of one real number". So it should be 48/2 * i. Right?

 
Neo7  posted on Apr 28, 2011 6:15:38 PM - Report post

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A complex number is written in the form a + bi.

2i is a complex number (not a real number) [Represented fully as 0+2i]

 
Paper_Masochist  posted on May 01, 2011 10:59:06 AM - Report post

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quote:
originally posted by Neo7

Back to this again.

I asked my mathematics professor (Ph.D. in mathematics). He says the answer is 288 becaues the divisor of the division problem is always the length of one real number unless specificed by a sub-equation completely encased in parenthesis/brackets (with the open parenthesis/bracket occuring immediately after the division symbol).

48/2(3+9) = 288
48/[2(3+9)] = 2

X(Y+Z) is shorthand for ((X x Y)+(X x Z)) it's called expanding the brackets.

So 48/2(3+9) = 2.

You can't say these are just algebra rules applied to standard math because the convention of assuming multiplication when there's no symbol specifically comes from algebra (2a is 2 x a)

 
Neo7  posted on May 01, 2011 12:14:26 PM - Report post

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quote:
originally posted by Paper_Masochist

quote:
originally posted by Neo7

Back to this again.

I asked my mathematics professor (Ph.D. in mathematics). He says the answer is 288 becaues the divisor of the division problem is always the length of one real number unless specificed by a sub-equation completely encased in parenthesis/brackets (with the open parenthesis/bracket occuring immediately after the division symbol).

48/2(3+9) = 288
48/[2(3+9)] = 2

X(Y+Z) is shorthand for ((X x Y)+(X x Z)) it's called expanding the brackets.

So 48/2(3+9) = 2.

You can't say these are just algebra rules applied to standard math because the convention of assuming multiplication when there's no symbol specifically comes from algebra (2a is 2 x a)

The way it's written, it would be (48/2)(3+9) for the distributive property. 48/2 is the monomial for the 3+9 part.

 
Paper_Masochist  posted on May 01, 2011 12:42:27 PM - Report post

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quote:
originally posted by Neo7

quote:
originally posted by Paper_Masochist

quote:
originally posted by Neo7

Back to this again.

I asked my mathematics professor (Ph.D. in mathematics). He says the answer is 288 becaues the divisor of the division problem is always the length of one real number unless specificed by a sub-equation completely encased in parenthesis/brackets (with the open parenthesis/bracket occuring immediately after the division symbol).

48/2(3+9) = 288
48/[2(3+9)] = 2

X(Y+Z) is shorthand for ((X x Y)+(X x Z)) it's called expanding the brackets.

So 48/2(3+9) = 2.

You can't say these are just algebra rules applied to standard math because the convention of assuming multiplication when there's no symbol specifically comes from algebra (2a is 2 x a)

The way it's written, it would be (48/2)(3+9) for the distributive property. 48/2 is the monomial for the 3+9 part.

So if it was written like this: 48/a(3+9) = x

You would instantly try to expand 48/a in 3 and 9? Once again this must go back into the way we were taught in certain countries because I aced expanded maths and that definitely looks like 2 is the multiplier to me.

Edit: Hmmm I can see how you're right too, it's so confusing because all mathematics I've done recently has been formatted entirely differently. I see it as:

48
--
2(3+4)

And the alternative as:

48
-- x (3+4)
2

[Edited by Paper_Masochist, 5/1/2011 12:50:24 PM]

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