SL 2.9—Exponential and logarithmic functions
- Syllabus
- First assessment 2021
- Objective
- —
- Level
- HL
Use inverse structure to connect exponential and logarithmic graphs
Use inverse structure to connect exponential and logarithmic graphs.
Exponential and logarithmic functions are inverses, so their graphs reflect in y=x and have linked domain/range restrictions.
Worked example
y=2ˣ has range y>0; y=log₂x has domain x>0.
Worked example
What does the reflection do? swaps x and y, turning one inverse graph into the other.
Common boundary
The logarithm is not defined for non-positive real inputs.