Inverse and Composite Inverse Functions

In summary, the conversation was about a student asking for feedback on their homework questions related to inverse and composite inverse functions. They received tips on not leaving negatives at the bottom of fractions and using the property f^{-1}h^{-1}=(hf)^{-1}. The student expressed gratitude for the help and felt more confident about their work.
  • #1
Matty R
83
0
Hello :smile:

I was wondering if someone could check my working and answers to these three homework questions. I've done the inverse functions in class, but not the composite inverse functions, if that's what they're called.

Homework Statement


http://img24.imageshack.us/img24/6035/question4t.jpg


Homework Equations


http://img25.imageshack.us/img25/2204/equations4.jpg


The Attempt at a Solution


http://img27.imageshack.us/img27/3402/attempt4a.jpg http://img27.imageshack.us/img27/9500/attempt4b.jpg


I'd appreciate any feedback. Parts a and b are just like I've done in class. Where I've left them is where we ended them in class. Part c is just a guess. I don't know if there is a special rule or something like that.

Thanks. :smile:
 
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  • #2
It looks fine to me. Just a few tips, (x-2)/(-3)=(2-x)/3 , you generally don't want to leave negatives hanging at the bottom of fractions, and also [itex]f^{-1}h^{-1}=(hf)^{-1}[/itex] may help you in the future.
 
  • #3
Focus said:
It looks fine to me. Just a few tips, (x-2)/(-3)=(2-x)/3 , you generally don't want to leave negatives hanging at the bottom of fractions, and also [itex]f^{-1}h^{-1}= (hf)^{-1}[/itex] may help you in the future.

Thanks for the reply. :smile:

I didn't know about not leaving negatives at the bottom of fractions. I'll make sure I don't do that in future. :smile:

I didn't know about the [itex](hf)^{-1}[/itex] bit either. I'm certain that will come up later in the course.

I really appreciate this. You've put my mind at ease. :smile:

Thanks again.
 

What are inverse functions?

Inverse functions are a type of mathematical function that "undoes" the action of another function. In other words, if a function f(x) transforms an input x into an output y, its inverse function f^-1(y) will take that output y and return the original input x.

How do you find the inverse of a function?

To find the inverse of a function, you can switch the x and y variables and solve for y. In other words, if the original function is f(x), the inverse function will be f^-1(x) = y. Then, you can solve for y in terms of x using algebraic manipulation.

What is the relationship between inverse functions and composite functions?

Composite functions are formed by combining two functions together, where the output of one function becomes the input of the other. Inverse functions are also related to composite functions, as the composition of a function and its inverse will always result in the original input. This means that (f^-1 ∘ f)(x) = x and (f ∘ f^-1)(x) = x for any input x.

Why are inverse functions important?

Inverse functions are important in mathematics and science because they allow us to "undo" the effects of a function and solve for the original input. They are also used in real-world applications, such as in cryptography and engineering, to encrypt and decrypt data.

Can any function have an inverse function?

Not all functions have an inverse function. For a function to have an inverse, it must be one-to-one, meaning that each input has a unique output. This ensures that the inverse function will also be a function. Additionally, the function must pass the horizontal line test, which means that no horizontal line intersects the graph of the function more than once.

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