SOLUTION: determine whether the equation defines y as a function of x y=x2 and x=y2

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Question 763502: determine whether the equation defines y as a function of x
y=x2 and x=y2
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Functions can only have one y-value per x-value.

y=x%5E2 is a function; works because it has two x-values per y
x=y%5E2=> y will be sqrt%28x%29 or -sqrt%28x%29; it's not a function because has two y-values per x, which, for functions, is against the rules
This will make sense if you graph y=x%5E2 and x=y%5E2 side by side.
Now try the "vertical line test".


as you can see, the vertical line intersects x=y%5E2 in two points