EX1 FIND THE 4th TERM BINOMIAL EXPANSION (3x+2y) ³ IN THE OF 3

Trigonometry (11th Edition)
11th Edition
ISBN:9780134217437
Author:Margaret L. Lial, John Hornsby, David I. Schneider, Callie Daniels
Publisher:Margaret L. Lial, John Hornsby, David I. Schneider, Callie Daniels
Chapter1: Trigonometric Functions
Section: Chapter Questions
Problem 1RE: 1. Give the measures of the complement and the supplement of an angle measuring 35°.
icon
Related questions
Question
---

## Binomial Expansion: Finding a Specific Term

### Example 1: Find the 4th Term in the Binomial Expansion of (3x + 2y)⁵

1. **Problem Statement:**
   \[
   \text{Find the 4th term in the binomial expansion of } (3x + 2y)^5.
   \]

2. **Solution:**
   - The expansion follows the binomial theorem formula:
     \[
     \binom{n}{r} \cdot (a)^{n-r} \cdot (b)^r
     \]
   - For the given problem, \(n = 5\), \(a = 3x\), and \(b = 2y\).
   - The 4th term corresponds to \(k = 3\) (since we start counting from 0).

   \[
   T_{k+1} = \binom{5}{3} \cdot (3x)^{5-3} \cdot (2y)^3
   \]

   - Calculating each part separately:
     \[
     \binom{5}{3} = \frac{5!}{3!(5-3)!} = \frac{5 \cdot 4 \cdot 3 \cdot 2 \cdot 1}{(3 \cdot 2 \cdot 1)(2 \cdot 1)} = 10
     \]

     \[
     (3x)^2 = 9x^2
     \]

     \[
     (2y)^3 = 8y^3
     \]

   - Combining these results:
     \[
     10 \cdot 9x^2 \cdot 8y^3 = 720x^2y^3
     \]

   - Therefore, the 4th term is:
     \[
     \boxed{720x^2y^3}
     \]

### Example 2: Find the 7th Term in the Binomial Expansion of (4x - y)⁷

1. **Problem Statement:**
   \[
   \text{Find the 7th term in the binomial expansion of } (4x - y)^7.
   \]

### Additional Information:
- The binomial coefficient is computed using:
Transcribed Image Text:--- ## Binomial Expansion: Finding a Specific Term ### Example 1: Find the 4th Term in the Binomial Expansion of (3x + 2y)⁵ 1. **Problem Statement:** \[ \text{Find the 4th term in the binomial expansion of } (3x + 2y)^5. \] 2. **Solution:** - The expansion follows the binomial theorem formula: \[ \binom{n}{r} \cdot (a)^{n-r} \cdot (b)^r \] - For the given problem, \(n = 5\), \(a = 3x\), and \(b = 2y\). - The 4th term corresponds to \(k = 3\) (since we start counting from 0). \[ T_{k+1} = \binom{5}{3} \cdot (3x)^{5-3} \cdot (2y)^3 \] - Calculating each part separately: \[ \binom{5}{3} = \frac{5!}{3!(5-3)!} = \frac{5 \cdot 4 \cdot 3 \cdot 2 \cdot 1}{(3 \cdot 2 \cdot 1)(2 \cdot 1)} = 10 \] \[ (3x)^2 = 9x^2 \] \[ (2y)^3 = 8y^3 \] - Combining these results: \[ 10 \cdot 9x^2 \cdot 8y^3 = 720x^2y^3 \] - Therefore, the 4th term is: \[ \boxed{720x^2y^3} \] ### Example 2: Find the 7th Term in the Binomial Expansion of (4x - y)⁷ 1. **Problem Statement:** \[ \text{Find the 7th term in the binomial expansion of } (4x - y)^7. \] ### Additional Information: - The binomial coefficient is computed using:
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Recommended textbooks for you
Trigonometry (11th Edition)
Trigonometry (11th Edition)
Trigonometry
ISBN:
9780134217437
Author:
Margaret L. Lial, John Hornsby, David I. Schneider, Callie Daniels
Publisher:
PEARSON
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781305652224
Author:
Charles P. McKeague, Mark D. Turner
Publisher:
Cengage Learning
Algebra and Trigonometry
Algebra and Trigonometry
Trigonometry
ISBN:
9781938168376
Author:
Jay Abramson
Publisher:
OpenStax
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781337278461
Author:
Ron Larson
Publisher:
Cengage Learning