0.9999.... = 1.0

[dsgrue3]

Jay520 said:

I'm not sure where you're getting f(x) = x^2 - 4 from. The function should just be x^2. The output of the function is 4. 

When you draw the inverse of a function, you have to restrict it to a one-to-one function before doing so. If the function is not one-to-one (which the quadratic function isn't), then it does not have an inverse.

I'm not taking the inverse of a function. 

x^2 = 4 subtract 4 from both sides to make x^2 - 4 = 0 then you can evaluate it at y=0.

Either way, -2 and 2 are solutions to both functions. f(x) = x^2, where f(x) = 4. This is just shifting the graph to evaluate at a different y - value.