Question

The functions $f$ and $g$ are defined as follows: \[f(x) = \sqrt{\dfrac{x+1}{x-1}}\quad\text{and}\quad g(x) = \dfrac{\sqrt{x+1}}{\sqrt{x-1}}.\]Explain why the functions $f$ and $g$ are not the same function. Please help, I can’t seem to find the domain of f :(

Answer 1

Answer:

The answer is "domain and range are different".

Step-by-step explanation:

Given:

$f(x) = \sqrt{\frac{x+1}{x-1}}\\\\g(x) =\frac{\sqrt{x+1}}{\sqrt{x-1}}$

Solve f(x) to find domain and range:

for element x: R:

⇒ $x \leq -1 \ \ \ and \ \ \ x > 1$ range:

$for \ \ f(x) \times element : 0 \leq f(x)< 1 \ \ \ or \ \ f(x)>1$

$g(x) =\frac{\sqrt{x+1}}{\sqrt{x-1}}$

Solve for domain:

⇒ $\ when \ x \ element \ R: \ \ \ x>1$  

Solve for range:  

⇒ $g(x) \times element$  R : $g(x)>1$

So, the value of the method f(x) and g(x) (range and domain) were different.