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

2 Answers
Jul 20, 2018

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

Jul 20, 2018

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]}