Math Problem Statement
Find f(g(x)) and g(f(x)) and determine whether the pair of functions f and g are inverses of each other.
f(x)=4x-5 and g(x)=(x+4)/5
Solution
To determine whether and are inverses of each other, we need to compute two compositions:
If both compositions simplify to , then and are inverses of each other.
Step 1: Find
Start by plugging into :
Substitute into the function :
Simplify the expression:
= \frac{4x + 16}{5} - 5$$ Now, rewrite $$5$$ as $$\frac{25}{5}$$ to subtract: $$f(g(x)) = \frac{4x + 16 - 25}{5} = \frac{4x - 9}{5}$$ So, $$f(g(x)) = \frac{4x - 9}{5}$$, which does not simplify to $$x$$. Therefore, $$f(g(x)) \neq x$$. ### Step 2: Find $$g(f(x))$$ Now, plug $$f(x)$$ into $$g(x)$$: $$g(f(x)) = g(4x - 5)$$ Substitute $$4x - 5$$ into the function $$g(x) = \frac{x + 4}{5}$$: $$g(4x - 5) = \frac{(4x - 5) + 4}{5}$$ Simplify the expression: $$= \frac{4x - 5 + 4}{5} = \frac{4x - 1}{5}$$ So, $$g(f(x)) = \frac{4x - 1}{5}$$, which does not simplify to $$x$$. Therefore, $$g(f(x)) \neq x$$. ### Conclusion: Since neither $$f(g(x))$$ nor $$g(f(x))$$ simplifies to $$x$$, the functions $$f(x) = 4x - 5$$ and $$g(x) = \frac{x + 4}{5}$$ are **not inverses** of each other. --- Would you like any further explanation or details? Here are 5 related questions to expand your understanding: 1. How do we determine if two functions are inverses of each other in general? 2. What would $$f(g(x))$$ and $$g(f(x))$$ look like if the functions were inverses? 3. Can the domain and range of inverse functions affect their properties? 4. How does graphing functions and their inverses help in understanding their relationship? 5. What are other methods to find the inverse of a function algebraically? **Tip**: Always check the domain of the functions when dealing with inverses, as domain restrictions can affect the outcome.Ask a new question for Free
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Math Problem Analysis
Mathematical Concepts
Algebra
Functions
Inverse Functions
Composition of Functions
Formulas
f(g(x)) = f((x + 4)/5)
g(f(x)) = g(4x - 5)
Theorems
Inverse Function Theorem
Properties of Function Composition
Suitable Grade Level
Grades 10-12
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