Question

How do I use graph of a quadratic equation like `f(x) = x^2 + 2` to find `f(2)`?

Answer 1

`f(2)` is putting the value for `x` into the equation. Using the graph - all you do is go to 2 on the `x` axis and read off the `y` value

Answer 2

`f(2) =6`

Explanation:

`f(x) = x^2+2`

The simplest way to find `f(2)` is to set `x=2` in the function.

`f(2) = 2^2+2 = 4+2 =6`

However, to solve this graphically, you could plot the graph of `f(x)` and the vertical line `x=2`. The solution will then be the intersection of the graphs. As below.

graph{(y-(x^2+2))(0.001y-x+2)=0 [-12.74, 12.59, -2.23, 10.42]}