Math logic between two concepts.

Ryan$

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Jan 25, 2019
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296
Hi guys !
Sorry for posting this, but I really need help to understand how things are going behind.

lets assume I was solving a problem in math, I arrived to equation X^2+y^2=M^2 which the logic of that problem tells me that I could use that equation Y=aX+b which a=2, b=5 !
my case is that .. can I assign in my equation X^2+y^2=M^2 , y=2X+5 ? if yes, then why?! why I'm not for example assigning the general equation Y=aX+b with any parameters (a,b) to my equation .. why exactly it's not allowed?

once again I'm not claiming that's wrong ! but I'm not convinced how from general equation Y=aX+b over specific parameters I can assign to my problem .. ! how is that logically correct?!


thanks alot
 

MarkFL

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Please post the original problem in its entirety.
 

Ryan$

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Jan 25, 2019
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given an equation like X^2+Y^2=R^2 afterwards in the video, the teacher said we have a case that y=0
then he said that case must satisfy also X^2+Y^2=R^2 , then he assigns y=0 into the equation and said we have X^2=R^2 .. my question is how really we can assign to the equation? isn't the equation X^2+Y^2=R^2 specified for specific case?
 

Subhotosh Khan

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given an equation like X^2+Y^2=R^2 afterwards in the video, the teacher said we have a case that y=0
then he said that case must satisfy also X^2+Y^2=R^2 , then he assigns y=0 into the equation and said we have X^2=R^2 .. my question is how really we can assign to the equation? isn't the equation X^2+Y^2=R^2 specified for specific case?
Which video?
 
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