Math Problem Statement

Suppose H(x)=(5x-4)^3. Find two functions f and g such that (fcirc g)(x)=H(x). Neither function can be the identity function. (There may be more than one correct answer.) f(x)=□ □ /□ sqrt(□ ) g(x)=□

Solution

To find two functions f(x)f(x) and g(x)g(x) such that (fg)(x)=H(x)=(5x4)3(f \circ g)(x) = H(x) = (5x - 4)^3, we need to express H(x)H(x) as a composition of two functions where neither function is the identity function. There can be more than one correct answer, but let's find one possible pair f(x)f(x) and g(x)g(x).

Step 1: Express H(x)=(5x4)3H(x) = (5x - 4)^3 as f(g(x))f(g(x)).

Let's consider g(x)=5x4g(x) = 5x - 4.

Then, f(x)f(x) should be the function that cubes its input, so: f(x)=x3f(x) = x^3

Step 2: Verify the composition.

Now, check if (fg)(x)(f \circ g)(x) gives us H(x)H(x): (fg)(x)=f(g(x))=f(5x4)=(5x4)3(f \circ g)(x) = f(g(x)) = f(5x - 4) = (5x - 4)^3

This matches H(x)H(x), so the functions f(x)=x3f(x) = x^3 and g(x)=5x4g(x) = 5x - 4 work correctly.

Final Answer:

  • f(x)=x3f(x) = x^3
  • g(x)=5x4g(x) = 5x - 4

Alternatively, you could also express H(x)H(x) differently, such as by choosing g(x)=x4g(x) = x - 4 and f(x)=(5x)3f(x) = (5x)^3, but the above choice is straightforward.

Would you like to explore other possibilities or any more details?

Here are 5 related questions:

  1. How can you determine if a function is a valid composition of two other functions?
  2. What happens if you change the order of composition fgf \circ g to gfg \circ f?
  3. How do you find the derivative of a composed function?
  4. Can f(x)f(x) and g(x)g(x) have domains that differ from H(x)H(x)?
  5. What are other possible pairs of f(x)f(x) and g(x)g(x) that satisfy the same composition?

Tip: When decomposing a function into compositions, it helps to think about breaking down the operations step by step, starting from the inside out.