Which points are on the graph of g(x) = (1/5)x?
Select each correct answer.
(3, 125) (-2,5) (1, 0) (-1, 5)?


Answer :

Given:

The function is

[tex]g(x)=(\dfrac{1}{5})^x[/tex]

To find:

The correct ordered pairs.

Solution:

We have,

[tex]g(x)=(\dfrac{1}{5})^x[/tex]

For x=3,

[tex]g(3)=(\dfrac{1}{5})^3[/tex]

[tex]g(3)=\dfrac{1}{125}[/tex]

So, the ordered pair is [tex](3,\dfrac{1}{125})[/tex].

For x=-2,

[tex]g(-2)=(\dfrac{1}{5})^{-2}[/tex]

[tex]g(-2)=(5)^2[/tex]             [tex][\because (\dfrac{a}{b})^{-n}=(\dfrac{b}{a})^n][/tex]

[tex]g(-2)=25[/tex]

So, the ordered pair is [tex](-2,25)[/tex].

For x=1,

[tex]g(1)=(\dfrac{1}{5})^1[/tex]

[tex]g(1)=\dfrac{1}{5}[/tex]

So, the ordered pair is [tex](1,\dfrac{1}{5})[/tex].

For x=-1,

[tex]g(-1)=(\dfrac{1}{5})^{-1}[/tex]

[tex]g(-1)=(5)^1[/tex]             [tex][\because (\dfrac{a}{b})^{-n}=(\dfrac{b}{a})^n][/tex]

[tex]g(-1)=5[/tex]

So, the ordered pair is (-1,5). This is the correct answer.

Therefore, the correct option is D.