Bah. Where did the -1 come from?

  • Thread starter Thread starter physicsnoob93
  • Start date Start date
Click For Summary
SUMMARY

The discussion centers on the confusion surrounding the conversion of the expression 1/(x+2) into its equivalent forms. A participant clarifies that the correct transformation is 1/(x+2) = 1/(2+x) = 1/(2-(-x)), emphasizing that the geometric series ratio "r" is -x/2, not x/2. Misinterpretation of the expression led to an incorrect conclusion, which was highlighted in green ink as the correct answer. This correction is crucial for understanding the manipulation of rational functions in algebra.

PREREQUISITES
  • Understanding of rational functions and their transformations
  • Familiarity with geometric series and their ratios
  • Basic algebraic manipulation skills
  • Knowledge of function notation and equivalence
NEXT STEPS
  • Study the properties of rational functions and their transformations
  • Learn about geometric series and how to identify their common ratios
  • Practice algebraic manipulation of expressions involving variables
  • Explore the concept of function equivalence in algebra
USEFUL FOR

Students learning algebra, educators teaching rational functions, and anyone seeking to clarify the manipulation of mathematical expressions.

physicsnoob93
Messages
169
Reaction score
0
http://img48.imageshack.us/img48/6110/qnisstb4.jpg

I always get the positive and negatives confused. I don't have a teacher to guide me so help would be appreciated. The correct answer is in green ink.

Thanks
 
Last edited by a moderator:
Physics news on Phys.org
At one point you have converted 1/(x+2) into (-1)/(2- x). That's wrong. That would be equal to 1/(x-2) not 1/(x+ 2). What you want, rather, is 1/(x+ 2)= 1/(2+x)= 1/(2-(-x)). Then dividing by numerator and denominator by 2: (1/2)/(1-(-x/2)). The "r" in your geometric series is -x/2, not x/2.
 

Similar threads

Replies
4
Views
4K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K