SOLUTION: X2+Y2=25 Is solving this problem considered a function? How do I plot a graph using a smooth curve for this problem? Ed

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Question 107025: X2+Y2=25
Is solving this problem considered a function?
How do I plot a graph using a smooth curve for this problem?
Ed
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
X%5E2%2BY%5E2=25
Solve for y as a function of x.
Y%5E2=25-X%5E2
Y=sqrt%2825-X%5E2%29 and Y=-sqrt%2825-X%5E2%29
Since the square root cannot be negative, then
25-X%5E2%3E=0
X%5E2%3C=25
abs%28X%29%3C=5
The domain of x is {-5,5} and the range of y is {-5,5}.
Choose several x's between -5 and 5 (-5,-4,-3,-2,-1,0,...) and calculate the y values.
Examples, when x=-4,
Y=sqrt%2825-X%5E2%29 and Y=-sqrt%2825-X%5E2%29
Y=sqrt%2825-%28-4%29%5E2%29 and Y=-sqrt%2825-%28-4%29%5E2%29
Y=sqrt%2825-%2816%29%5E2%29 and Y=-sqrt%2825-%2816%29%5E2%29
Y=3 and Y=-3
So the ordered pairs (3,4) and (3,-4) are on your curve.
More points make for a smoother curve.
When you graph the function, you will see that it is the top and bottom of a circle centered at 0,0 with a radius of 5.
+graph%28+300%2C+300%2C+-6%2C+6%2C+-6%2C+6%2C+sqrt%2825-x%5E2%29+%2C+-sqrt%2825-x%5E2%29%29+