Math Problem Statement

If f(x) = 2x + 1 and g(x) = 2x^2 - 1, find f(g(-2)).

Solution

We are given two functions, f(x)=2x+1f(x) = 2x + 1 and g(x)=2x21g(x) = 2x^2 - 1, and asked to find f(g(2))f(g(-2)).

Here’s how we can solve this step by step:

  1. First, find g(2)g(-2): g(x)=2x21g(x) = 2x^2 - 1 Substituting x=2x = -2: g(2)=2(2)21=2(4)1=81=7g(-2) = 2(-2)^2 - 1 = 2(4) - 1 = 8 - 1 = 7

  2. Now that we know g(2)=7g(-2) = 7, we substitute 77 into the function f(x)f(x): f(x)=2x+1f(x) = 2x + 1 So, f(7)=2(7)+1=14+1=15f(7) = 2(7) + 1 = 14 + 1 = 15.

Thus, f(g(2))=15f(g(-2)) = 15.

Would you like more details or explanations?

Here are 5 follow-up questions you might explore:

  1. What happens if g(x)g(x) is a more complex polynomial?
  2. Can you find g(f(2))g(f(-2))?
  3. How would you approach solving this problem if the functions were given as trigonometric functions instead?
  4. What would be the result if f(x)f(x) were a logarithmic function and g(x)g(x) stayed the same?
  5. How does function composition affect the domain and range of a function?

Tip: When composing functions, always evaluate the innermost function first!

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Math Problem Analysis

Mathematical Concepts

Function Composition
Quadratic Function
Linear Function

Formulas

f(x) = 2x + 1
g(x) = 2x^2 - 1

Theorems

Function Composition Rule

Suitable Grade Level

Grades 9-11