How to solve what should be a simple variant of a quadratic

  • Thread starter Thread starter Justin R
  • Start date Start date
  • Tags Tags
    Quadratic
AI Thread Summary
The discussion revolves around solving a quadratic-like equation of the form Ax^2 + Bx + Cx^(-1) + D = 0, where the C/x term complicates the solution. The solution proposed involves transforming the equation into a cubic form by multiplying through by x, resulting in Ax^3 + Bx^2 + Dx + C = 0. It is important to note that while x=0 may satisfy the cubic equation, it is not a valid solution for the original equation. This approach simplifies the problem and allows for easier resolution of the equation. The transformation effectively addresses the challenge posed by the inverse term.
Justin R
Messages
2
Reaction score
0
Hi everyone,

For some reason I can't put this together in my head. I have a series of equations that can be solved directly, but my resulting equation is of the form:

Ax^2 + Bx + Cx^(-1) + D = 0

Obviously the C/x term is the one throwing the wrench in the works here. Could anyone point me in the right direction?

Thanks in advance!

-Justin
 
Physics news on Phys.org
Justin R said:
Hi everyone,

For some reason I can't put this together in my head. I have a series of equations that can be solved directly, but my resulting equation is of the form:

Ax^2 + Bx + Cx^(-1) + D = 0

Obviously the C/x term is the one throwing the wrench in the works here. Could anyone point me in the right direction?

Thanks in advance!

-Justin

Nevermind... It's very easy. Turn it into a cubic equation by multiplying through by X, resulting in the readily solvable:

Ax^3 + Bx^2 + Dx + C = 0
 
And be sure to note that while x= 0 might satisfy the third degree equation, it cannot be a solution to the first equation.
 
I picked up this problem from the Schaum's series book titled "College Mathematics" by Ayres/Schmidt. It is a solved problem in the book. But what surprised me was that the solution to this problem was given in one line without any explanation. I could, therefore, not understand how the given one-line solution was reached. The one-line solution in the book says: The equation is ##x \cos{\omega} +y \sin{\omega} - 5 = 0##, ##\omega## being the parameter. From my side, the only thing I could...
Back
Top