Math Problem Statement

Solution

The given functions are f(x)=2x1f(x) = 2x - 1 and g(x)=x22x+1g(x) = x^2 - 2x + 1. We need to find the following:

  1. (fg)(x)(f \circ g)(x)
  2. (gf)(x)(g \circ f)(x)
  3. (ff)(1)(f \circ f)(-1)
  4. (gg)(1)(g \circ g)(1)
  5. (fg)(1.5)(f \circ g)(1.5)

Let's solve these step by step:

1. (fg)(x)(f \circ g)(x)

This means f(g(x))f(g(x)).

First, calculate g(x)g(x): g(x)=x22x+1g(x) = x^2 - 2x + 1

Now, substitute g(x)g(x) into ff: f(g(x))=f(x22x+1)f(g(x)) = f(x^2 - 2x + 1) f(x22x+1)=2(x22x+1)1f(x^2 - 2x + 1) = 2(x^2 - 2x + 1) - 1 =2x24x+21= 2x^2 - 4x + 2 - 1 =2x24x+1= 2x^2 - 4x + 1

Thus, (fg)(x)=2x24x+1(f \circ g)(x) = 2x^2 - 4x + 1

2. (gf)(x)(g \circ f)(x)

This means g(f(x))g(f(x)).

First, calculate f(x)f(x): f(x)=2x1f(x) = 2x - 1

Now, substitute f(x)f(x) into gg: g(f(x))=g(2x1)g(f(x)) = g(2x - 1) g(2x1)=(2x1)22(2x1)+1g(2x - 1) = (2x - 1)^2 - 2(2x - 1) + 1 =(2x1)24x+2+1= (2x - 1)^2 - 4x + 2 + 1 =4x24x+14x+2+1= 4x^2 - 4x + 1 - 4x + 2 + 1 =4x28x+4= 4x^2 - 8x + 4

Thus, (gf)(x)=4x28x+4(g \circ f)(x) = 4x^2 - 8x + 4

3. (ff)(1)(f \circ f)(-1)

This means f(f(1))f(f(-1)).

First, calculate f(1)f(-1): f(1)=2(1)1f(-1) = 2(-1) - 1 =21= -2 - 1 =3= -3

Now, substitute 3-3 into ff: f(3)=2(3)1f(-3) = 2(-3) - 1 =61= -6 - 1 =7= -7

Thus, (ff)(1)=7(f \circ f)(-1) = -7

4. (gg)(1)(g \circ g)(1)

This means g(g(1))g(g(1)).

First, calculate g(1)g(1): g(1)=122(1)+1g(1) = 1^2 - 2(1) + 1 =12+1= 1 - 2 + 1 =0= 0

Now, substitute 00 into gg: g(0)=022(0)+1g(0) = 0^2 - 2(0) + 1 =0+0+1= 0 + 0 + 1 =1= 1

Thus, (gg)(1)=1(g \circ g)(1) = 1

5. (fg)(1.5)(f \circ g)(1.5)

This means f(g(1.5))f(g(1.5)).

First, calculate g(1.5)g(1.5): g(1.5)=(1.5)22(1.5)+1g(1.5) = (1.5)^2 - 2(1.5) + 1 =2.253+1= 2.25 - 3 + 1 =0.25= 0.25

Now, substitute 0.250.25 into ff: f(0.25)=2(0.25)1f(0.25) = 2(0.25) - 1 =0.51= 0.5 - 1 =0.5= -0.5

Thus, (fg)(1.5)=0.5(f \circ g)(1.5) = -0.5

Summary:

  1. (fg)(x)=2x24x+1(f \circ g)(x) = 2x^2 - 4x + 1
  2. (gf)(x)=4x28x+4(g \circ f)(x) = 4x^2 - 8x + 4
  3. (ff)(1)=7(f \circ f)(-1) = -7
  4. (gg)(1)=1(g \circ g)(1) = 1
  5. (fg)(1.5)=0.5(f \circ g)(1.5) = -0.5

Do you want details or have any questions?

Related Questions:

  1. What is the derivative of (fg)(x)(f \circ g)(x)?
  2. What is the inverse of f(x)f(x)?
  3. Find (gf)(2)(g \circ f)(-2).
  4. Calculate (ff)(2)(f \circ f)(2).
  5. Find the critical points of (gg)(x)(g \circ g)(x).
  6. What is (gf)(3)(g \circ f)(3)?
  7. Determine the range of (fg)(x)(f \circ g)(x).
  8. Calculate (fg)(0)(f \circ g)(0).

Tip:

When solving composite functions, always start by computing the inner function first and then substitute its result into the outer function.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Composite Functions
Quadratic Equations

Formulas

Composite function formula (f ◦ g)(x)
(g ◦ f)(x)
(f ◦ f)(x)
(g ◦ g)(x)

Theorems

-

Suitable Grade Level

High School