Function notation, domain and range
Work out values of f(x) from a rule, find the input that gives an output, write the domain of a fraction and a square root, and read the range from a graph.
- UK: Year 10
- France: grade 8
- Germany: grade 8
- Iran: grade 10
- Afghanistan: grade 10
- Syria: grade 9
- Palestine: grade 9
- Ukraine: grade 7
- Russia: grade 7
Guide
Read f(x) as "f of x": a machine called f that takes x and gives an output. In f(x) = x2 − 2x, to find f(−1) put −1 in place of x and work it out.
The domain is every input the machine can accept; the range (of a function) is every output it can give. A denominator must not be 0, and the number under a square root must not be negative.
Read the range from a graph: the heights the curve reaches. The domain is read along the x-axis and the range up the y-axis.