Math Problem Statement

Find f left parenthesis g left parenthesis x right parenthesis right parenthesis spaceif

f left parenthesis x right parenthesis space equals space fraction numerator x cubed plus 10 over denominator x minus 4 end fraction

and

g left parenthesis x right parenthesis space equals space square root of 3 x minus 5 end root

Solution

We are tasked with finding f(g(x))f(g(x)), where:

  • f(x)=x3+10x4f(x) = \frac{x^3 + 10}{x - 4}
  • g(x)=3x5g(x) = \sqrt{3x - 5}

To find f(g(x))f(g(x)), we will substitute g(x)g(x) into f(x)f(x).

Step-by-step solution:

  1. Substitute g(x)=3x5g(x) = \sqrt{3x - 5} into f(x)f(x):

    f(g(x))=f(3x5)f(g(x)) = f\left( \sqrt{3x - 5} \right)

    Since f(x)=x3+10x4f(x) = \frac{x^3 + 10}{x - 4}, we replace xx in f(x)f(x) with g(x)g(x):

    f(g(x))=(3x5)3+103x54f(g(x)) = \frac{\left( \sqrt{3x - 5} \right)^3 + 10}{\sqrt{3x - 5} - 4}

  2. Simplify the numerator:

    The cube of 3x5\sqrt{3x - 5} is:

    (3x5)3=(3x5)3/2\left( \sqrt{3x - 5} \right)^3 = (3x - 5)^{3/2}

    So the numerator becomes:

    (3x5)3/2+10(3x - 5)^{3/2} + 10

  3. Simplify the denominator:

    The denominator is already in a simplified form:

    3x54\sqrt{3x - 5} - 4

Thus, the final expression for f(g(x))f(g(x)) is:

f(g(x))=(3x5)3/2+103x54f(g(x)) = \frac{(3x - 5)^{3/2} + 10}{\sqrt{3x - 5} - 4}


Would you like further explanation or clarifications on this?

Here are some related questions you might find interesting:

  1. What is the behavior of f(x)f(x) as xx approaches 4?
  2. How do we find the domain of the composite function f(g(x))f(g(x))?
  3. What is the value of f(g(x))f(g(x)) when x=5x = 5?
  4. How can we differentiate the composite function f(g(x))f(g(x))?
  5. What is the inverse of f(x)f(x) and how does it relate to g(x)g(x)?

Tip: To find the domain of a composite function like f(g(x))f(g(x)), first ensure the domain of g(x)g(x) is valid, and then verify if the output of g(x)g(x) is within the domain of f(x)f(x).

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Composite Functions
Functions
Simplification

Formulas

f(x) = (x^3 + 10) / (x - 4)
g(x) = sqrt(3x - 5)

Theorems

Composition of Functions

Suitable Grade Level

Grades 9-12