SOLUTION: Determine whether the equation defines y as a function of x. x2 + y = 25

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Question 1174857: Determine whether the equation defines y as a function of x.
x2 + y = 25

Answer by Theo(13342) (Show Source):
You can put this solution on YOUR website!
solve for y to get:
y = 25 - x^2

the definition of a function is that, each and every value of y has one and only one value of x.

that applies to this equation.

you can pick any value of x and you will get one and only one value of y.

for example:

x = 5, y = 25 - 25 = 0

x = 6, y = 25 - 36 = -11.

if you graph the equation, you will see something like this:

the vertical line test will pass only one value of y for each and every value of x.

this means there is one and only one value of y for each and every value of x.

for example, a vertical line at x = 3 intersects with only one value of y at y = 25 - 3^2 = = 25 - 9 = 16.

here is a definition of a function from the internet.

http://www.berkeleycitycollege.edu/wp/wjeh/files/2012/01/note_function.pdf