Function notation

The equation of a straight line can also be written in the form \(f(x) = mx + c\).

This is called function notation and is just another way of expressing the relationship between two variables.

Therefore, in general \(y = f(x)\).

If \(f(x)=4x+1\), calculate \(f(3)\)

Now try the example question below.

\(f(3)\) means you substitute \(x=3\) into \(4x+1\)

\(f(3)=4(3)+1\)

\(=12+1\)

= \(13\)

Question

If \(f(x) = 3x - 5\), calculate \(f( - 2)\).