yr2 chap 2 functions + graphs

• domain refers to the x coordinates
• range refers to the y coordinates
• the domain of f(x) is the range of f-1(x)

  the range of f(x) is the domain of f-1(x)
• it is usually easier to find the domain of a function than to find the range, so an easier way to find the range of a function is to find the domain of the inverse function and change the notation, as they are equivalent
• to find the domain of a function you can often use the fact that it is impossible to divide by zero, so any fractions involving x on the denominator cannot have the x value which would make the denominater zero
• a function must be continuous and a one-to-one mapping
• one-to-one mapping means for every value of x there is one value of y, and vice versa