SOLUTION: Is this a function: {(x.y) | x^2 +(y-1)^2 = 4}

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Question 694712: Is this a function: {(x.y) | x^2 +(y-1)^2 = 4}
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
{(x.y) | x%5E2+%2B%28y-1%29%5E2+=+4}
What is a Function?
A function relates an+input to an+output.
A function is a rule that assigns uniquely to a member of domain+set, a member of the range set. The key word is "uniquely".
So if you assign say x=2 as well as x=-2 to number y=1, then you have a rule, but not a function. That is the logic behind the vertical+line+test. If you draw a vertical line and it intersects the graph of the function in two+distinct+points, then you can see that it means you have assigned both of these points to the point where your vertical line crosses the x-axis.
An example of this is the circle, and you have a circle.