Question

A logarithmic function of base ‘3’ has a vertical asymptote at the line x=1. Its graph contains the point (2,1). What is the equation of the function?

1) f(x)=log3 (x+1)
2) f(x)=log3(x-1)+1
3) f(x)=log3(x+1)+1
4) f(x)=log3(x)+1

Answer 1

9514 1404 393

Answer:

2) f(x) = log3(x -1) +1

Explanation:

The vertical asymptote of the log function is normally x=0. In this function, it is moved to the right 1 unit. That is accomplished by replacing the function argument x with (x-1). Only one answer choice matches:

f(x) = log3(x -1) +1