Prove that two equations are inverses of each other.

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Homework Help Overview

The discussion revolves around proving that two functions, f(x) = 9 - x^2 (for x ≥ 0) and g(x) = sqrt(9 - x), are inverses of each other. The participants are exploring the conditions under which two functions can be considered inverses.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants are attempting to compute f(g(x)) and are discussing the simplification of the expression. There are questions about whether to open brackets and clarifications on terminology regarding functions versus equations.

Discussion Status

The discussion is ongoing, with some participants providing guidance on simplification and emphasizing the need to also verify g(f(x)). There is an acknowledgment of the terminology used in the context of inverse functions.

Contextual Notes

There is a focus on ensuring the conditions for inverse functions are met, and participants are navigating through the implications of their calculations and definitions.

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Homework Statement


f(x) = 9-x^2, x ≥ 0. g(x) = sqrt (9-x)

Homework Equations


Two equations are inverses of each other if f(g(x)) = g(f(x)) = x.

The Attempt at a Solution



f(g(x)) = 9 - (sqrt (9-x))^2

= 9 - (9-x)
 
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Open the brackets?
 
Hmm?
 
Physics-Pure said:

Homework Statement


f(x) = 9-x^2, x ≥ 0. g(x) = sqrt (9-x)

Homework Equations


Two equations are inverses of each other if f(g(x)) = g(f(x)) = x.

The Attempt at a Solution



f(g(x)) = 9 - (sqrt (9-x))^2

= 9 - (9-x)
So close! Simplify the above.

Don't forget that you also have to show that g(f(x)) = x.
 
BTW, we don't normally say that equations are inverses of each other - we say that functions are inverses of each other.
 

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