What is the proper way to present mathematical problems on online forums?

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Homework Help Overview

The discussion revolves around a mathematical problem involving absolute values and the determination of a variable, h, under specific conditions. Participants are exploring the relationships between the variables and the implications of their signs.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the manipulation of the equation |a| = |h| |b| to derive h, questioning how to ensure h remains negative. There are attempts to clarify the conditions under which h can be negative and the implications of removing absolute value signs.

Discussion Status

There is an active exploration of the mathematical relationships involved, with some participants providing guidance on how to approach the problem. Multiple interpretations of the equations and their implications are being discussed, particularly regarding the signs of the variables.

Contextual Notes

Some participants express concerns about the clarity of the problem statement, suggesting that adherence to forum standards for presenting problems is important for effective discussion.

Muhammad Danish
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Homework Statement


upload_2018-6-27_23-29-31.png


Homework Equations


Is my solution correct? If not then please point out the mistakes and help me solve this question in the right way. Thanks in advance.

The Attempt at a Solution


upload_2018-6-27_23-31-3.png
 

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|a| = |b| |h|
so
|h| = |a| / |b|
and h<0
 
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.Scott said:
|a| = |b| |h|
so
|h| = |a| / |b|
and h<0
After finding h, can we solve this question by matrix method? (The way I did)
 
You have h = -|b|/|a|.
It should be h = -|a|/|b|.

Then solve with b = a/h
 
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.Scott said:
You have h = -|b|/|a|.
It should be h = -|a|/|b|.

Then solve with b = a/h
If we make |h| the subject, it will be |h|= |a| / |b|. The answer will be positive. So | | signs will reverse the signs and give a negative value of h?
 
Right. We need to make h negative.
|a|/|b| is positive over positive, which is positive.

Per the problem, we need h to be negative...
So, h = -|a|/|b|
 
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.Scott said:
Right. We need to make h negative.
|a|/|b| is positive over positive, which is positive.

Per the problem, we need h to be negative...
So, h = -|a|/|b|
How will it become negative?

If I use the equation |a| = |h| |b| then how can I get a negative value of h?
 
Muhammad Danish said:
How will it become negative?

If I use the equation |a| = |h| |b| then how can I get a negative value of h?

By using the equation: h = -|a|/|b|

Here's the sequence:
|a| = |h| |b|
|a|/|b| = |h|
so either h = |a|/|b|
or h = -|a|/|b|

But we know from the problem statement that it must be negative.
 
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.Scott said:
By using the equation: h = -|a|/|b|
By removing ''| |'' from h, the other side will become negative?
 
  • #10
Muhammad Danish said:
By removing ''| |'' from h, the other side will become negative?
I added some text to my last post.
Here it is again:

Here's the whole sequence:
|a| = |h| |b|
|a|/|b| = |h|
so either h = |a|/|b|
or h = -|a|/|b|

But we know from the problem statement that it must be negative.
 
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  • #11
.Scott said:
I added some text to my last post.
Here it is again:

Here's the whole sequence:
|a| = |h| |b|
|a|/|b| = |h|
so either h = |a|/|b|
or h = -|a|/|b|

But we know from the problem statement that it must be negative.
Like this?
upload_2018-6-28_0-27-19.png
 

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  • #12
Yes!
 
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  • #13
.Scott said:
Yes!
Thank you!
 
  • #14
Muhammad Danish said:

Homework Statement


View attachment 227388

Homework Equations


Is my solution correct? If not then please point out the mistakes and help me solve this question in the right way. Thanks in advance.

The Attempt at a Solution


View attachment 227389

Your problem is totally unreadable. Please take the trouble to adhere to the PF standard, by typing out the statement of the problem. If you cannot do that, you should at least make sure you take a proper photo that will come out readable by the rest of the world.
 

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