MHB Roots of Polynomial: Find $\frac{1}{A}+\frac{1}{B}+\frac{1}{C}$

  • Thread starter Thread starter anemone
  • Start date Start date
  • Tags Tags
    Polynomial Roots
Click For Summary
The discussion centers on finding the values of A, B, and C in the context of the polynomial equation x^3 - 22x^2 + 80x - 67, whose roots are p, q, and r. The equation is expressed in terms of partial fractions, leading to the relationship between the coefficients and the roots. Participants analyze the structure of the polynomial and apply techniques from algebra to derive the values of A, B, and C. Ultimately, the question posed is whether the sum of the reciprocals, 1/A + 1/B + 1/C, equals 244. The conclusion is that the correct answer is indeed 244.
anemone
Gold Member
MHB
POTW Director
Messages
3,851
Reaction score
115
Let $p,\,q$ and $r$ be the distinct roots of the polynomial $x^3-22x^2+80x-67$. It is given that there exist real numbers $A,\,B$ and $C$ such that

$\dfrac{1}{s^3-22s^2+80s-67}=\dfrac{A}{s-p}+\dfrac{B}{s-q}+\dfrac{C}{s-r}$ for all $s\not \in \{p,\,q,\,r\}$. What is $\dfrac{1}{A}+\dfrac{1}{B}+\dfrac{1}{C}$?
 
Mathematics news on Phys.org
Is answer 244?
 
I have been insisting to my statistics students that for probabilities, the rule is the number of significant figures is the number of digits past the leading zeros or leading nines. For example to give 4 significant figures for a probability: 0.000001234 and 0.99999991234 are the correct number of decimal places. That way the complementary probability can also be given to the same significant figures ( 0.999998766 and 0.00000008766 respectively). More generally if you have a value that...

Similar threads

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