Question

How do you sketch the graph of `y=log_2x-4`?

Answer 1

`x>0`. As `x to 0, y to -oo, x = 0 darr` is the asymptote.
As #x to oo, y to oo. The graph is inserted.

Explanation:

graph{ (y-log x/log 2 - 4)=0 [-20, 20, -10, 10]}

Use `log_b a = log_ca/log_c b`.

`y = log_2 x-4 =log x/log 2 - 4`:

The graph, for this form in common logarithm, is inserted.