How do you evaluate function notation?

1 Answer
Feb 1, 2015

In fuction notation, you have a variable (often the function #f#) which values depends on those of another variable (often the indipendent variable #x#).

When we write something like #f(x)=x^2-3x+2#, we mean that for every number #x#, we must behave in the same way to evaluate #f#: in this case, we must sum the square of that number, then subtract its triple, and then add 2.

Evaluating a function simply means to substitute the exact value in the generic expression of the function. In my example, if you want to calculate #f(5)#, you simply need to replace every #x# with a "5", and so

#x^2-3x+2 \rightarrow (2)^2-3\cdot 2 +2 = 4-6+2=0#