Question

What is the zero of the logarithmic function: f(x) = log3 (x-1)?

Answer 1

y = f(x)
then
y = log(3x)

WE can't have log of zero or a neg number therefore all values: x > 0

Start with x = .22, using a calc, enter log(3*.2) = -.22
x = .6; log(3*.6) = +.25 
x = 1; log(3*1) = +.48
x = 1.4 log(3*1.4) = +.62
After this the curve flattens out so we can jump to x = 2
x = 2 log(3*2) = .78

x = 4 log(3*4) = 1.08
Continuing like this make a table
x | y
-------
.2 |-.22
.6 |+.26
1.0|+.48
1.4|+.62
2.0|+.78
4.0|1.08
6.0|1.26


Plot this on graph, scaled about like this.