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

Jul 20, 2018

$f \left(2\right)$ 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

Jul 20, 2018

$f \left(2\right) = 6$

#### Explanation:

$f \left(x\right) = {x}^{2} + 2$

The simplest way to find $f \left(2\right)$ is to set $x = 2$ in the function.

$f \left(2\right) = {2}^{2} + 2 = 4 + 2 = 6$

However, to solve this graphically, you could plot the graph of $f \left(x\right)$ 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]}