Math Problem Statement

Diketahui fungsi f(x) = 2x^2 - 5x + 3 dan g(x) = x + 4. Tentukan (f + g)(6) dan (f ⋅ g)(-2).

Solution

The problem given is as follows:

  1. Given functions: f(x)=2x25x+3f(x) = 2x^2 - 5x + 3 and g(x)=x+4g(x) = x + 4 Find:
    • (f+g)(6)(f + g)(6)
    • (fg)(2)(f \cdot g)(-2)

Let's solve each part:

Part (a): (f+g)(6)(f + g)(6)

To find (f+g)(6)(f + g)(6), we first calculate f(6)f(6) and g(6)g(6) and then add them:

  1. Calculate f(6)f(6): f(6)=2(6)25(6)+3=23630+3=7230+3=45f(6) = 2(6)^2 - 5(6) + 3 = 2 \cdot 36 - 30 + 3 = 72 - 30 + 3 = 45

  2. Calculate g(6)g(6): g(6)=6+4=10g(6) = 6 + 4 = 10

  3. Add f(6)f(6) and g(6)g(6): (f+g)(6)=f(6)+g(6)=45+10=55(f + g)(6) = f(6) + g(6) = 45 + 10 = 55

Thus, (f+g)(6)=55(f + g)(6) = 55.

Part (b): (fg)(2)(f \cdot g)(-2)

To find (fg)(2)(f \cdot g)(-2), we first calculate f(2)f(-2) and g(2)g(-2), then multiply them:

  1. Calculate f(2)f(-2): f(2)=2(2)25(2)+3=24+10+3=8+10+3=21f(-2) = 2(-2)^2 - 5(-2) + 3 = 2 \cdot 4 + 10 + 3 = 8 + 10 + 3 = 21

  2. Calculate g(2)g(-2): g(2)=2+4=2g(-2) = -2 + 4 = 2

  3. Multiply f(2)f(-2) and g(2)g(-2): (fg)(2)=f(2)g(2)=212=42(f \cdot g)(-2) = f(-2) \cdot g(-2) = 21 \cdot 2 = 42

Thus, (fg)(2)=42(f \cdot g)(-2) = 42.

Summary

  • (f+g)(6)=55(f + g)(6) = 55
  • (fg)(2)=42(f \cdot g)(-2) = 42

Would you like further explanations on any of these steps?

Here are some related questions that might deepen your understanding:

  1. How do you find the sum and product of two functions in general?
  2. What are some properties of functions that help simplify calculations?
  3. How would (fg)(x)(f - g)(x) and (f/g)(x)(f / g)(x) be calculated for these functions?
  4. What happens if you apply transformations to f(x)f(x) and g(x)g(x) before combining them?
  5. Can you find the domain and range for the sum and product of f(x)f(x) and g(x)g(x)?

Tip: When dealing with function operations, calculate each function individually at the given point before combining them for clarity.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Function Operations
Algebra

Formulas

(f + g)(x) = f(x) + g(x)
(f ⋅ g)(x) = f(x) ⋅ g(x)

Theorems

Function Addition
Function Multiplication

Suitable Grade Level

Grades 9-10