Beginner's linear algebra question

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SUMMARY

This discussion centers on solving linear equations to find polynomial coefficients in linear algebra. The user seeks assistance with formulating and solving systems of linear equations for given points. Specifically, they need to determine the coefficients for a first-degree polynomial using points (1,3) and (2,4), and for a third-degree polynomial using points (0,1), (1,10), (2,33), and (3,64). The hints provided clarify the process of substituting known values into the polynomial equations to isolate the unknown coefficients.

PREREQUISITES
  • Understanding of linear equations and systems
  • Familiarity with polynomial functions and their degrees
  • Basic algebraic manipulation skills
  • Knowledge of coordinate geometry
NEXT STEPS
  • Learn how to solve systems of linear equations using matrices
  • Study polynomial interpolation techniques, such as Lagrange interpolation
  • Explore the concept of polynomial regression for data fitting
  • Practice deriving polynomial equations from given data points
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Students in introductory linear algebra courses, educators teaching polynomial functions, and anyone looking to strengthen their understanding of systems of equations and polynomial modeling.

lezardo
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Hi everyone! I recently started taking a basic linear algebra course at my university and I'm already having problems. I used to be pretty good at math in general, but I guess I've unlearned everything over the years. Any help would be appreciated, thanks!

A.
Two points on a plane with the coordinates (x0,y0) and (x1,y1) define a graph with the form:
y = c1x + c0 (polynomial of the 1. degree).

1)Formulate a system of linear equations to find the coefficients of this function.
2) Solve this system of equations to find the function which runs through the points (1;3) and (2;4).


B.
n + 1 points on a plane [(x0, y0), (x1, y1),…; (xn, yn)] define a polynomial of the nth degree:
y = cnx^n + …+ c2x^2 + c1x + c0.

1)Formulate a system of linear equations to find the coefficients of this polynomial.
2) Solve this system to find the polynomial which runs through the points (0;1), (1;10), (2,33) and (3,64).


P.S. Hints or something like that would also be great. It's really frustrating sitting here with nothing but "duhhhhh" in my head.
 
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Do you understand the question? It's asking you to find the equation of the polynomial whose graph passes through those points. Here is a hint on part A. The equation you are trying to find is y = c1x + c0 (you are trying to find the c's). You know that the point (x0, y0) satisfies this equation and so does (x1, y1). So you can write, for example
y0 = c1x0 + c0
where y0 and x0 are KNOWN and c1 and c0 are UNKNOWN.
Can you figure it out now?
 
Do you understand the question? It's asking you to find the equation of the polynomial whose graph passes through those points. Here is a hint on part A. The equation you are trying to find is y = c1x + c0 (you are trying to find the c's). You know that the point (x0, y0) satisfies this equation and so does (x1, y1). So you can write, for example
y0 = c1x0 + c0
where y0 and x0 are KNOWN and c1 and c0 are UNKNOWN.
Can you figure it out now?

Well, i feel stupid. It was staring me right in the face. Thanks a lot!
 

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