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March 9th, 2011, 03:46 PM   #1
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points of intersections

Hey guys I know this is going to seem like a retarted question but here goes.
determine the point of intersection of f(x)=5+?x+1 and g(x)=x+1
when you set them equal the equation it ends in is
0=x^2-9x+15
how do i resolve for the x and y values for the point of intersection?
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March 9th, 2011, 03:58 PM   #2
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Re: points of intersections

Are you sure you have f(x) copied correctly? I ask because I get a different equation in x when I equate f and g, and it seems odd it would be given with like terms left to combine. My best guess is that you are given:





Equate f and g:



Subtract 5 from both sides:



Square both sides, keeping in mind extraneous solutions may be introduced, if they are less than 4 (a square root cannot be negative):



Write in standard quadratic form:



Apply quadratic formula:



Discard root less than 4:



Now, for the y-coordinate use either or .
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March 10th, 2011, 08:32 AM   #3
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Re: points of intersections

Hello, functionman!

Quote:
\,+\,1" />

^2\,-\,9x\,+\,15 \:=\:0" />









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March 10th, 2011, 08:46 AM   #4
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Re: points of intersections

I guess your years as a professor has better equipped you to translate what people mean to write vs. what they actually write!
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