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I need help
Center?
Radius?

I need help Center? Radius?-example-1
User Bowersbros
by
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1 Answer

23 votes
23 votes

Answers:

Center = (1, 5)

Radius = 3

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Work Shown:


x^2+y^2-2x-10y+17 = 0\\\\(x^2-2x)+(y^2-10y)+17 = 0\\\\(x^2-2x+0)+(y^2-10y+0)+17 = 0\\\\(x^2-2x+1-1)+(y^2-10y+25-25)+17 = 0\\\\(x^2-2x+1)+(y^2-10y+25)+(-1-25+17) = 0\\\\(x-1)^2+(y-5)^2-9 = 0\\\\(x-1)^2+(y-5)^2 = 9\\\\(x-1)^2+(y-5)^2 = 3^2

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Step-by-step explanation:

The idea is to complete the square for the x and y terms separately.

Notice the jump from step 3 to step 4 has the first 0 turn into 1-1, and the second 0 turn into 25-25. This is to help complete the square for each part.

The x^2-2x+1 factors to (x-1)^2 and y^2-10y+25 factors to (y-5)^2

Once we reach the last step, we have something in the form
(x-h)^2+(y-k)^2 = r^2

Center = (h,k) = (1,5)

Radius = r = 3

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