Question 1174857
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:


<img src = "http://theo.x10hosting.com/2021/021102.jpg" >


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.


<a href = "http://www.berkeleycitycollege.edu/wp/wjeh/files/2012/01/note_function.pdf" target = "_blank">http://www.berkeleycitycollege.edu/wp/wjeh/files/2012/01/note_function.pdf</>