Checking and securing understanding of function notation
I can define and use function notation.
- Year 11
Checking and securing understanding of function notation
I can define and use function notation.
Lesson details
Key learning points
- There is a shorthand for writing a function
- The notation means that the whole function does not need to be written out each time
- The notation should always be defined at the start
- It is possible to substitute the notation for the function it represents
Keywords
Function - A function is a mathematical relationship that uniquely maps values of one set to the values of another set.
Domain - The domain of a function is the set of values that the mapping is performed on.
Range - The range of a function is the set of values mapped to by the function and the stated domain.
Inverse function - An inverse function reverses the mapping of the original function.
Common misconception
Pupils may confuse the domain and the range.
Drawing the graph of the function and labelling the axes correctly will help pupils connect domain and range.
Licence
Prior knowledge starter quiz
6 Questions
Q1.When graphing the linear equation $$y=6x-10$$, what is the value of the $$y$$ coordinate when $$x=3$$?
Q2.When graphing the linear equation $$y=6x-10$$, what is the value of the $$y$$ coordinate when $$x=-1$$?
Q3.Match these key words to their definitions.
domain -Â the set of values for a function that the mapping is performed on
function -Â a relationship which uniquely maps values in one set to another
inverse function -Â a relationship which reverses the mapping of the original function
range -Â the set of values mapped to, by the function
Q4.When we graph the equation $$y= x^2$$, what is the minimum value (i.e. the smallest value of the $$y$$ coordinate)?
Q5.Which of these is not a valid input for $$x$$ in the equation $$y = \frac{1}{2x}$$ ?
Q6.What does $$\text{sin}^{-1} (x)$$ mean?
Assessment exit quiz
6 Questions
Q1.If $$\text{f}(x)= 4(x-2)$$, which is the correct notation for the inverse function $$\text{f}$$ inverse of $$x$$ ?
Q2.If $$\text{g}(4) = 6$$, then $$\text{g}^{-1}(6) =$$ .
Q3.If $$\text{f}(x)= 3x - 5$$, $$\text{g}(x)= 10-2x$$ and $$\text{h}(x)= x^2 + 3$$. Match up these functions with their outputs.
$$\text{f}(-2)$$ -Â $$-11$$
$$\text{g}(-2)$$ -Â $$14$$
$$\text{h}(-2)$$ -Â $$7$$
$$\text{f}(1)$$ -Â $$-2$$
$$\text{g}(1)$$ -Â $$8$$
$$\text{h}(1)$$ -Â $$4$$