SOLUTION: how i do this? find the equation of a circle centered at the origin, and having radius 1 find the equation of a circle centered at the origin and having radius 5 find the

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Question 551080: how i do this?
find the equation of a circle centered at the origin, and having radius 1
find the equation of a circle centered at the origin and having radius 5
find the equation of a circle centered at the origin, and having radius ,/19
find the equation of a circle centered at the origin and having radius 3,/7

Answer by AnlytcPhil(1807)   (Show Source): You can put this solution on YOUR website!
Substitute the value of the radius for r in

x² + y² = r²

For instance, to get the answer to 

find the equation of a circle centered at the origin and having radius 5
just substitute 5 for r and get

x² + y² = 5²

and then do one more step, change 5² to 25

x² + y² = 25

That's the equation.

That's all there is to it!

Edwin

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