How do you graph logarithms without a calculator?

Question

I need to graph y = -1 + log(base2)x

Answer 1

There are just a few things you need to know

1) all log graphs have the same shape - increasing function with decreasing gradient
2) as x goes to zero logx goes to negative infinity
3) at x = 1, logx = 0 regardless of the base
In your case at x = 1, y = -1
4) logx = 1 when x = base, in your case x = 2
so y = 0 at x = 2
5) then as x goes to posivite infinity, logx goes to positive infinity
6) the function does not exist for negative x
7) once you have a couple of critical points, just sketch through them.

Answer 2

Graphing Logs Calculator

Answer 3

Just use computer software, like MS Excel. Or you can see logarithm table. Hints: to get base 2 logarithm, you should divide numbers in the table (usually in base 10) with log 2 (base 10).