for the function y=ln(x-1)+2 which of the following statements is true

a. the domain is all real numbers and the range is [2, infinity)
b. the domain is (-1, infintity} and the range is all real numbers
c. the domain is (1, infinity) and the range is [2, infinity)
d. the domain is (1, infinity) and the range is all real numbers

Respuesta :

gmany

Answer:

d. the domain is (1, infinity) and the range is all real numbers

Step-by-step explanation:

The domain of a logarithmic function

[tex]f(x)=\ln(x)[/tex]

is the set of all positive numbers

[tex]D:\ x>0\Rightarrow x\in\mathbb{R}^+[/tex]

The range of a logarithmic function

[tex]f(x)=\ln(x)[/tex]

is the set of all real numbers

[tex]R:\ y\in\mathbb{R}[/tex]

We have:

[tex]y=\ln(x-1)+2[/tex]

DOMAIN

[tex]x-1>0[/tex]            add 1 to both sides

[tex]x-1+1>0+1\\\\x>1[/tex]

[tex]D:x>0\Rightarrow x\in(1,\ \infty)[/tex]

RANGE

[tex]f(x)=\ln(x)\to f(x)+2=\ln(x)+2[/tex]

The graph shifted 2 units up. The range no change.

[tex]R:\ y\in\mathbb{R}[/tex]