Inverses of Exponential Functions

about 25 min · 5 short parts · stop after any part

2^x

and

\log_2 x

undo each other, like × and ÷.
By the end you can spot exponential vs log tables, test if two functions are inverses, and find an inverse with algebra.

The path

1
Logs, fast refresh
You can switch $\log_2 8 = 3$ into $2^3 = 8$ and back.
2
What an inverse does
You can swap a table and picture the mirror graph.
3
Exponential, log, or neither?
You can name the type from a table and list inverse points.
4
Inverses undo each other
You can test if two functions are inverses with $g(f(x))$ .
5
Find the inverse with algebra
You can find $f^{-1}(x)$ for $b^{kx}$ and $a\log_b x$ .