EDGE Math 8

Function Notations

Suppose an equation represents a function. The notation $f (x),$ which is read as "f of x" represents the value of the function at a number x. In this case, f names a function. Functions are often named by the letters f, g, and h.

Suppose you are given the equation $y = 16 - x^{2},$ which defines y as a function of x. In function notation, the equation becomes $f (x) = 16 - x^{2} .$ The notation $f (x)$ corresponds to the value of y for a given value of x. This function is read as $" f of x equals 16 - x^{2} . "$

To find $f (1),$ which is the value of the function at 1, you must substitute 1 for x. Hence, $f (x) = 16 - x^{2}$ becomes:

f (x) = f (1) = 16 - 1^{2} = 16 - 1 = 15.

Since $f (1) = 15,$ the value of the function at 1 is 15.

You can find other function values by substituting the specified input values for x.