SOLUTION: hello im in high school righ now, learning about conics and i have a question on how to find an equaion of a circle if: =========== =========== =========== == circle with cente

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: hello im in high school righ now, learning about conics and i have a question on how to find an equaion of a circle if: =========== =========== =========== == circle with cente      Log On


   

Question 144056: hello
im in high school righ now, learning about conics
and i have a question on how to find an equaion of a circle if:
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circle with center at (-5,1) and radius 6
also what it he line(s) of symmetry?
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thank you so much
and i will appreciate very much if you could
respond soon as possible
i have a quiz tomorrow
thank you !!!
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
The equation of any circle is %28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2 where (h,k) is the center and r is the radius. So in your case, the center is (-5,1) which means that h=-5 and k=1. Also the radius is 6, so r=6.


This means that the equation is %28x-%28-5%29%29%5E2%2B%28y-1%29%5E2=6%5E2 which simplifies to %28x%2B5%29%5E2%2B%28y-1%29%5E2=36




Since we're dealing with a circle, there are an infinite number of lines of symmetry (ie you can fold the circle in half along any line as long as that line goes through the center). If you're looking for the vertical and horizontal lines of symmetry, then they are in the form of x=h and y=k. So the vertical line of symmetry is x=-5 and the horizontal line of symmetry is y=1.