Math Problem Statement

Evaluate functions using given formulas for different values of x and b. The problems include finding f(x), h(b), g(2w), and composite functions like f(g(x)).

Solution

Let's go through each of the function evaluation problems in the image and solve them step by step:


1. Given the function f(x)=3x5f(x) = 3x - 5, find f(4)f(4):

Substitute x=4x = 4 into f(x)f(x): f(4)=3(4)5=125=7f(4) = 3(4) - 5 = 12 - 5 = 7


2. Find the value of h(b)=3b22b+1h(b) = 3b^2 - 2b + 1 when b=3b = -3:

Substitute b=3b = -3 into h(b)h(b): h(3)=3(3)22(3)+1=3(9)+6+1=27+6+1=34h(-3) = 3(-3)^2 - 2(-3) + 1 = 3(9) + 6 + 1 = 27 + 6 + 1 = 34


3. Find g(2w)g(2w) when g(x)=x22x+1g(x) = x^2 - 2x + 1:

Substitute x=2wx = 2w into g(x)g(x): g(2w)=(2w)22(2w)+1=4w24w+1g(2w) = (2w)^2 - 2(2w) + 1 = 4w^2 - 4w + 1


4. Given f(x)=2x2+4x3f(x) = 2x^2 + 4x - 3, find f(2a+3)f(2a + 3):

Substitute x=2a+3x = 2a + 3 into f(x)f(x): f(2a+3)=2(2a+3)2+4(2a+3)3f(2a + 3) = 2(2a + 3)^2 + 4(2a + 3) - 3 First, expand (2a+3)2(2a + 3)^2: (2a+3)2=4a2+12a+9(2a + 3)^2 = 4a^2 + 12a + 9 Now, substitute: f(2a+3)=2(4a2+12a+9)+4(2a+3)3f(2a + 3) = 2(4a^2 + 12a + 9) + 4(2a + 3) - 3 =8a2+24a+18+8a+123= 8a^2 + 24a + 18 + 8a + 12 - 3 =8a2+32a+27= 8a^2 + 32a + 27


5. Given f(x)=x24f(x) = x^2 - 4 and g(x)=x+1g(x) = x + 1, evaluate:

  • a. f(2)f(-2): f(2)=(2)24=44=0f(-2) = (-2)^2 - 4 = 4 - 4 = 0

  • b. g(3)g(3): g(3)=3+1=4g(3) = 3 + 1 = 4

  • c. (fg)(1)(f - g)(-1): First, evaluate f(1)f(-1) and g(1)g(-1): f(1)=(1)24=14=3f(-1) = (-1)^2 - 4 = 1 - 4 = -3 g(1)=1+1=0g(-1) = -1 + 1 = 0 Now, (fg)(1)=f(1)g(1)=30=3(f - g)(-1) = f(-1) - g(-1) = -3 - 0 = -3

  • d. f(g(2))f(g(-2)): First, find g(2)g(-2): g(2)=2+1=1g(-2) = -2 + 1 = -1 Now, substitute into f(x)f(x): f(1)=(1)24=14=3f(-1) = (-1)^2 - 4 = 1 - 4 = -3


Let me know if you'd like any of these steps detailed further or have any questions!

Related Questions:

  1. How do you evaluate functions with two variables like f(a,b)f(a, b)?
  2. What happens if the function has a piecewise definition?
  3. Can functions involve trigonometric terms, and how would we evaluate those?
  4. How do you determine if a function is injective or surjective?
  5. What are composite functions, and how are they evaluated?

Tip:

When working with composite functions like f(g(x))f(g(x)), always solve the inside function first, then substitute into the outer function.

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Math Problem Analysis

Mathematical Concepts

Function Evaluation
Substitution
Algebra
Composite Functions

Formulas

f(x) = 3x - 5
h(b) = 3b^2 - 2b + 1
g(x) = x^2 - 2x + 1
f(x) = 2x^2 + 4x - 3
f(x) = x^2 - 4
g(x) = x + 1

Theorems

Substitution Method for Evaluating Functions

Suitable Grade Level

Grades 9-12