To interpret an equation given in function notation, it is necessary to understand what both sides of
f(x)=k mean. For example, consider the following equation.
f(3)=12
Here,
f(3) denotes that the function's input is
x=3 and that
12 is the output corresponding to this input.
f(3)=12⇓The output of f when x=3 is 12.
Now, consider a different scenario. Let
w(t)=200t be a function that describes the number of words Kevin reads in
t minutes. The following statements are true for this function.
w(4)andw(t)=900
Here,
w(4) is the number of words that Kevin reads in
4 minutes and can be found by for
t=4. However, the input is not a particular number in the second statement. In such cases, the statement can be interpreted as a question.
w(t)=900⇓For which value of tis theoutput equal to 900?
Based on the context, the second statement asks how many minutes it takes Kevin to read
900 words. To of
t, the equation
w(t)=900 has to be solved for
t.