Difference between revisions of "2017 AMC 12B Problems/Problem 6"

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==Solution==
 
==Solution==
Solution 1
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Because the two points are on a diameter, the center must be halfway between them at the point (4,3). The distance from (0,0) to (4,3) is 5 so the circle has radius 5. Thus, the equation of the circle is <math>(x-4)^2+(y-3)^2=25</math>.  
Because the two points are a diameter the center must be half way between them at the point (4,3). The distance from (0,0) to (4,3) is 5 therefore the circle has a radius of 5. The equation of the circle can thus be written as (x-4)^2+(y-3)^2=25. To find the x intercept y must be 0, so (x-4)^2+(0-3)^2=25.
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Then (x-4)^2=16.
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To find the x-intercept, y must be 0, so <math>(x-4)^2+(0-3)^2=25</math>, so <math>(x-4)^2=16</math>, <math>x-4=4</math>, <math>x=8</math>.
x-4=4.
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x=8
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Written by: SilverLion
  
 
==See Also==
 
==See Also==
 
{{AMC12 box|year=2017|ab=B|num-b=5|num-a=7}}
 
{{AMC12 box|year=2017|ab=B|num-b=5|num-a=7}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Revision as of 10:01, 17 February 2017

Problem 6

The circle having $(0,0)$ and $(8,6)$ as the endpoints of a diameter intersects the $x$-axis at a second point. What is the $x$-coordinate of this point?

Solution

Because the two points are on a diameter, the center must be halfway between them at the point (4,3). The distance from (0,0) to (4,3) is 5 so the circle has radius 5. Thus, the equation of the circle is $(x-4)^2+(y-3)^2=25$.

To find the x-intercept, y must be 0, so $(x-4)^2+(0-3)^2=25$, so $(x-4)^2=16$, $x-4=4$, $x=8$.

Written by: SilverLion

See Also

2017 AMC 12B (ProblemsAnswer KeyResources)
Preceded by
Problem 5
Followed by
Problem 7
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions

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