Solving Equations: Understanding Factoring and Finding Solutions

  • Context: High School 
  • Thread starter Thread starter Femme_physics
  • Start date Start date
  • Tags Tags
    Factoring
Click For Summary

Discussion Overview

The discussion revolves around solving the equation x(x-3)² = 0, focusing on the process of factoring and understanding the implications of root multiplicity in relation to the solutions of the equation. Participants explore the nature of the solutions and their representation.

Discussion Character

  • Mathematical reasoning
  • Conceptual clarification
  • Homework-related

Main Points Raised

  • One participant proposes that the equation can be factored as x(x-3)(x-3) = 0, leading to the solutions x1 = 3, x2 = 3, and x3 = 0.
  • Another participant agrees and suggests that the solutions can also be expressed as x = 3 (with multiplicity 2) and x = 0, noting the significance of root multiplicity in graph behavior.
  • There is a discussion about whether it is acceptable to list the solutions as x1 = 3 and x2 = 0 without repeating 3, with multiple participants affirming this approach.
  • Participants express appreciation for the supportive environment and the mentoring aspect of the discussion.

Areas of Agreement / Disagreement

Participants generally agree on the interpretation of the solutions and the concept of multiplicity, but there is no explicit consensus on the preferred way to present the solutions.

Contextual Notes

Participants discuss the implications of root multiplicity on the graph of the equation, but the discussion does not delve into specific mathematical proofs or formal definitions.

Who May Find This Useful

This discussion may be useful for students learning about polynomial equations, factoring, and the concept of root multiplicity in mathematics.

Femme_physics
Gold Member
Messages
2,548
Reaction score
1
So let's say I have an equation

x(x-3)2 = 0

I can factor it out to x(x-3)(x-3) = 0

Since there are two 3's in parenthesis, does this mean that the answers are

x1 = 3
x2 = 3
and
x3 = 0
 
Mathematics news on Phys.org
Yes! :smile:
 
Femme_physics said:
So let's say I have an equation

x(x-3)2 = 0

I can factor it out to x(x-3)(x-3) = 0

Since there are two 3's in parenthesis, does this mean that the answers are

x1 = 3
x2 = 3
and
x3 = 0
Yes, but you can also say that the solutions are x = 3 and x = 0. If you want to be picky, you can say that 3 is a root of multiplicity 2 of your equation.

Multiplicity of roots plays a role in the shape of a graph. For y = x(x-3)2, the x-intercepts are at x = 0 and x = 3. Since the multiplicity of the root at 0 is one, the graph of this equation looks a lot like the graph of y = x for x near 0.

Since the multiplicity of the root at 3 is two, the graph of this equation looks like the graph of y = (x - 3)2 for x near 3. IOW, near 3 the graph of the original equation looks like a parabola whose vertex is at (3, 0), and that opens upward. For values of x that aren't close to 3 and aren't close to 0, the effects of the cubic equation are dominant over the local effects near 0 and 3.
 
I like Serena said:
Yes! :smile:
Wait, so there are 3 solutions, but since two of the solutions are the same, can I say
x1 = 3
and
x2 = 0

Without writing 3 two times as the answer?
 
Yes, but you can also say that the solutions are x = 3 and x = 0
That'd be better! And thanks for the rest of the explanation! :)
 
Femme_physics said:
Wait, so there are 3 solutions, but since two of the solutions are the same, can I say
x1 = 3
and
x2 = 0

Without writing 3 two times as the answer?

Again yes! :smile:

You appear to understand perfectly! :)
 
I love it how you always make me feel awesome, ILS, even for simple stuff. You're an exemplary teacher and mentor! :)
 
Femme_physics said:
I love it how you always make me feel awesome, ILS, even for simple stuff. You're an exemplary teacher and mentor! :)

I like the feedback :smile:
I'm learning here too you know!
Trying to earn a superhero homework helper suit (with a big "HH" at front and undies over costume-- yep) :P
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 17 ·
Replies
17
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 19 ·
Replies
19
Views
4K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 2 ·
Replies
2
Views
6K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K