How to Construct Specific Degree 3 Polynomials with Given Conditions?

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Homework Help Overview

The discussion revolves around constructing specific degree 3 polynomials, p(x) and q(x), that satisfy a set of given conditions related to their values and derivatives at certain points. The original poster expresses difficulty in finding a method to derive these polynomials using their linear algebra resources.

Discussion Character

  • Exploratory, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss the formulation of the polynomials based on provided conditions and the potential creation of a linear system of equations to solve for the coefficients. There is also a mention of vector spaces in relation to the problem.

Discussion Status

The conversation is ongoing, with participants exploring different interpretations of the problem and seeking clarification on the relationships between the polynomial coefficients and the conditions given. Some guidance has been offered regarding setting up equations, but no consensus or final solution has emerged.

Contextual Notes

The original poster notes a time constraint for presenting their findings, which adds urgency to their request for assistance. They also mention that their textbook does not cover the specific type of polynomial problem they are facing.

Mathman23
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Urgent: n-degree polynomial problems

Hi

I know I have asked this before, but I haven't been able to solve the problem using the tools that I have.
Let me recap

I have been tasked to find two polynomials of degree 3 p(x) and q(x) complies with the following conditions.

p( - 1) = 1 , p'(-1) = 0 , q(1) = 3, q'(1) = 0, p(0) = q(0), p'(0) = q'(0)

I'm told that the resulting two polynomials of degree 3 are:

p(x) = (2 + s - 2t) x^3 + (3 + 2s - 3t) x^2 + s*x + t

q(x) = (-6 + s + 2t) x^3 + (9 - 2s - 3t) x^2 + s*x +t

where s,t belong to R.

I have looked through my linear algebra text-book several times, but can't find a method on howto build polynomials which resemble p(x) and q(x).

Is there anybody who can direct me to a method on howto build the to above polynomials ?

Sincerley and Best Regards,

Fred

p.s. Thanks again for all Your answers in the past they mean the world to me :-)

p.p.s. I have done some research now and s, t are the socalled roots of the the cubic polynomial.
 
Last edited:
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Suppose p(x) = ax^3 + bx^2 + cx + d and q(x) = ex^3 + fx^2 + gx + h. Use the other information given to create a linear system of equations with the coefficients of p and q as variables.
 
Hi and thanks for Your answer,

The equations inside the parantheses are they derived from the system of linear equation?

Hi I'm told that all this has something to do with vector spaces. But exactly how I'm a bit unsure of :-(

Sincerley and Best Regards,

Fred

Muzza said:
Suppose p(x) = ax^3 + bx^2 + cx + d and q(x) = ex^3 + fx^2 + gx + h. Use the other information given to create a linear system of equations with the coefficients of p and q as variables.
 
Last edited:
My problem is that first of all my Linear Algebra textbook doesn't deal with these kinds of polynomials.
Futher I need to present the calculations on friday if I can't I fail.

Hope there is somebody who can direct me on howto obtain the final solution for this problem ? :-)

Thank You and God Bless You all.

Sincerely
Fred

Mathman23 said:
Hi

I know I have asked this before, but I haven't been able to solve the problem using the tools that I have.
Let me recap

I have been tasked to find two polynomials of degree 3 p(x) and q(x) complies with the following conditions.

p( - 1) = 1 , p'(-1) = 0 , q(1) = 3, q'(1) = 0, p(0) = q(0), p'(0) = q'(0)

I'm told that the resulting two polynomials of degree 3 are:

p(x) = (2 + s - 2t) x^3 + (3 + 2s - 3t) x^2 + s*x + t

q(x) = (-6 + s + 2t) x^3 + (9 - 2s - 3t) x^2 + s*x +t

where s,t belong to R.

I have looked through my linear algebra text-book several times, but can't find a method on howto build polynomials which resemble p(x) and q(x).

Is there anybody who can direct me to a method on howto build the to above polynomials ?

Sincerley and Best Regards,

Fred

p.s. Thanks again for all Your answers in the past they mean the world to me :-)
 

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