Math Problem Statement

Given f(x) , find g(x) and h(x) such that f(x)=g(h(x)) and neither g(x) nor h(x) is solely x.

f(x)=−4/3x−2

Solution

To find functions g(x)g(x) and h(x)h(x) such that f(x)=g(h(x))f(x) = g(h(x)) and neither g(x)g(x) nor h(x)h(x) is solely xx, we need to decompose the function f(x)=43x2f(x) = -\frac{4}{3}x - 2 into a composition of two functions.

Step-by-Step Solution

Given: f(x)=43x2f(x) = -\frac{4}{3}x - 2

We want to express f(x)f(x) as g(h(x))g(h(x)) where neither g(x)g(x) nor h(x)h(x) is just xx.

Step 1: Identify potential structures for h(x)h(x) and g(x)g(x)

Let's choose a function h(x)h(x) that is neither too simple nor too complex, and then find g(x)g(x) accordingly.

A good strategy is to let h(x)h(x) be a linear function, because the given function f(x)f(x) is also linear. We could choose:

h(x)=ax+bh(x) = ax + b

And then g(x)g(x) will be:

g(x)=cx+dg(x) = c \cdot x + d

Step 2: Choose specific forms for h(x)h(x) and g(x)g(x)

Let's try h(x)=2x+3h(x) = 2x + 3 and find g(x)g(x) such that g(h(x))=f(x)g(h(x)) = f(x).

Substitute h(x)h(x) into g(x)g(x):

f(x)=g(h(x))=g(2x+3)f(x) = g(h(x)) = g(2x + 3)

Now, let’s find g(x)g(x).

We need: g(2x+3)=43x2g(2x + 3) = -\frac{4}{3}x - 2

To match this, set up a function g(x)g(x):

If g(x)=23x+cg(x) = -\frac{2}{3}x + c, substituting x=2x+3x = 2x + 3 gives:

g(2x+3)=23(2x+3)+cg(2x + 3) = -\frac{2}{3}(2x + 3) + c

Simplify: g(2x+3)=43x2+cg(2x + 3) = -\frac{4}{3}x - 2 + c

To match f(x)=43x2f(x) = -\frac{4}{3}x - 2, set c=0c = 0.

So, g(x)=23xg(x) = -\frac{2}{3}x.

Step 3: Verify the decomposition

Now we have:

h(x)=2x+3,g(x)=23xh(x) = 2x + 3, \quad g(x) = -\frac{2}{3}x

Then: g(h(x))=g(2x+3)=23(2x+3)=43x2g(h(x)) = g(2x + 3) = -\frac{2}{3}(2x + 3) = -\frac{4}{3}x - 2

Which is exactly f(x)f(x).

Conclusion

Thus, one possible pair of functions g(x)g(x) and h(x)h(x) such that f(x)=g(h(x))f(x) = g(h(x)) are:

g(x)=23x,h(x)=2x+3\boxed{g(x) = -\frac{2}{3}x, \quad h(x) = 2x + 3}

Neither g(x)g(x) nor h(x)h(x) is solely xx.

Would you like more details or have any questions?

Here are 5 related questions to explore further:

  1. How can you find a different pair of functions g(x)g(x) and h(x)h(x) for the same f(x)f(x)?
  2. What is the composition of two quadratic functions to form a cubic function?
  3. Can you decompose a nonlinear function into two linear functions?
  4. How does the chain rule in calculus relate to function composition?
  5. What are the properties of invertible functions in function decomposition?

Tip: When decomposing functions, start by looking for simpler component functions (like linear or quadratic ones) that, when combined, match the original function.

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Math Problem Analysis

Mathematical Concepts

Function Composition
Linear Functions

Formulas

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Theorems

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Suitable Grade Level

High School