Grade 12 Math (inverse of functions)

In summary, the given expression can be rewritten as ##y= \sqrt{ \frac{x-1}{x+1} }## and, after some algebraic manipulation, the inverse function can be found to be ##x= -\frac{y^2+1}{y^2-1}##.
  • #1
Ethan_Tab
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Member warned about posting homework in a technical section
f(x)=[((x-1)/(x+1))+((x-1)/(x+1))]1/2

What is F-1(x)

No matter what I try I am unable to isolate for y after switching x's with y's. Any ideas?
 
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  • #2
Ethan_Tab said:
f(x)=[((x-1)/(x+1))+((x-1)/(x+1))]1/2
The innermost expression is ##\frac{x - 1}{x + 1} + \frac{x - 1}{x + 1}##, which can be simplified. Is that what you meant to write?
Ethan_Tab said:
What is F-1(x)

No matter what I try I am unable to isolate for y after switching x's with y's. Any ideas?

BTW, this looks like a homework problem, so I'm moving this thread.
 
  • #3
This is a pretty common problem. I'll work on a similar one as an example.
##y = \sqrt{ \frac{x-1}{x+1} } ##
##y^2 = \frac{x-1}{x+1},\, y\geq 0##
## y^2 = \frac{x+1}{x+1}-\frac{2}{x+1}##
## y^2-1 = -\frac{2}{x+1}##
##x+1 = -\frac{2}{y^2-1}##
##x= -\frac{2}{y^2-1}-1=-\frac{2}{y^2-1}-\frac{y^2-1}{y^2-1}=-\frac{y^2+1}{y^2-1}##
 

Related to Grade 12 Math (inverse of functions)

1. What is the inverse of a function?

The inverse of a function is a mathematical operation that reverses the output of a given function. It is denoted as f-1(x) and is found by swapping the x and y variables in the original function and solving for y.

2. How do you find the inverse of a function?

To find the inverse of a function, you first need to determine if the function is one-to-one, meaning that each input has a unique output. If it is one-to-one, you can swap the x and y variables and solve for y to find the inverse. If it is not one-to-one, you may need to restrict the domain of the function to make it one-to-one before finding the inverse.

3. What is the relationship between a function and its inverse?

The inverse of a function is essentially the "mirror image" of the original function. This means that the domain and range of the original function become the range and domain of the inverse, respectively. Additionally, the composition of a function and its inverse will always result in the input value.

4. How do you graph the inverse of a function?

To graph the inverse of a function, you can use a graphing calculator or manually swap the x and y coordinates of points on the original function's graph. This will result in a reflection of the original graph over the line y=x. It is also important to note any restrictions on the domain and range of the original function when graphing the inverse.

5. What is the importance of inverse functions in mathematics?

Inverse functions are important in mathematics because they allow us to undo operations and solve equations. They also have many real-world applications, such as in physics, where inverse functions are used to model inverse relationships between variables. Inverse functions are also necessary for understanding logarithms and exponential functions, which are used extensively in science and engineering.

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