Solving a quadratic Lagrange interpolant , How ?

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Discussion Overview

The discussion revolves around solving a quadratic Lagrange interpolant using MATLAB, focusing on a specific problem involving interpolation of velocity values at given time points. Participants share their attempts and seek assistance in correcting their calculations.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Technical explanation

Main Points Raised

  • One participant shares their attempt at solving the problem, providing equations based on given velocity values at specific time points.
  • The participant expresses confusion about their results, noting discrepancies between their calculated value and the expected answer.
  • Another participant raises a question regarding the interpretation of the results, suggesting that two answers might be expected due to the nature of the intervals provided.
  • Repeated requests for assistance indicate urgency and a need for clarification on the problem-solving process.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the correct approach or solution, as there are multiple interpretations of the results and ongoing confusion about the calculations.

Contextual Notes

The discussion includes potential misunderstandings about the application of the Lagrange interpolant and the setup of the equations, but these issues remain unresolved.

Who May Find This Useful

Students or individuals working on interpolation problems, particularly those involving quadratic functions and MATLAB programming, may find this discussion relevant.

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how would i solve it using MATLAB ? I tried many times but i didnt get the same answer may anyone help me please ?
 
Last edited by a moderator:
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Anyone please ? I have to submit this in 2 days please help...


My attempt is as follows

v(15)=a0+a1(t)+a2(t)=24
a0+a1(15)+a2(15)^2=24


v(18)=a0+a1(t)+a2(t)=37
a0+a1(18)+a2(18)^2=37

v(22)=a0+a1(t)+a2(t)=25
a0+a1(22)+a2(22)^2=25


I then wrote it in the Matrix Form

a=[1 15 225;1 18 324;1 22 484]
b=[24;27;35]
x=a/b

Results:

a0=-323.8571
a1=38.9048
a2=-1.0476


Using the following Equation:

v(16)=-323.8571+(38.9048*16)+(-1.0476*(16^2))=
30.4341 s which is wrong ofcourse The ans is 20.846 so wheres my mistake
 
The value 26m/s is obtained twice

First interval: 15 -18
Second Interval: 18-22

So i should be getting two answers is that so ?
 
Anyone please help me submission is tommrow
 

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