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26 votes
26 votes
Express your answer as a polynomial in standard form

f(x) = 4x + 5

g(x) = x2 + 4x + 2

Find: f(g(x))

User Sahil Dahiya
by
2.3k points

1 Answer

20 votes
20 votes

Answer:

f(g(x)) = 4x² + 16x + 13

Explanation:

Given the composition of functions f(g(x)), for which f(x) = 4x + 5, and g(x) = x² + 4x + 2.

Definitions:

  • The polynomial in standard form has terms that are arranged by descending order of degree.
  • In the composition of function f with function g, which is alternatively expressed as f ° g, is defined as (f ° g)(x) = f(g(x)).

In evaluating composition of functions, the first step is to evaluate the inner function, g(x). Then, we must use the derived value from g(x) as an input into f(x).

Solution:

Since we are not provided with any input values to evaluate the given composition of functions, we can express the given functions as follows:

f(x) = 4x + 5

g(x) = x² + 4x + 2

f(g(x)) = 4(x² + 4x + 2) + 5

Next, distribute 4 into the parenthesis:

f(g(x)) = 4x² + 16x + 8 + 5

Combine constants:

f(g(x)) = 4x² + 16x + 13

Therefore, f(g(x)) as a polynomial in x that is written in standard form is: 4x² + 16x + 13.

User MANCHUCK
by
3.1k points