how to solve this

[allegansveritatem]

Here is the problem:


Not knowing a Lagrage interpolation polynomial from a barn door, here is nevertheless the attempt I made to solve this:



I don't know if the author of this problem expects the students to know how to build this Lagrange thing or not. Above is the only thing I could think of doing.

 

[Deleted member 4993]

Here is the problem:
View attachment 13627

Not knowing a Lagrage interpolation polynomial from a barn door, here is nevertheless the attempt I made to solve this:

View attachment 13628

I don't know if the author of this problem expects the students to know how to build this Lagrange thing or not. Above is the only thing I could think of doing.

The last line you wrote (hand-written) does not make sense. It reduces to f(x) = 1

You could start to distinguish between a Lagrange interpolation polynomial from a barn door, by reading:

http://mathworld.wolfram.com/LagrangeInterpolatingPolynomial.html

 

[Dr.Peterson]

I think you have the answer, and just didn't write what you meant in the last line. Compare that with the previous line, and replace some of those x's with c's ...

You don't need to know anything more than you were told in order to answer the question.

 

[allegansveritatem]

The last line you wrote (hand-written) does not make sense. It reduces to f(x) = 1

You could start to distinguish between a Lagrange interpolation polynomial from a barn door, by reading:

http://mathworld.wolfram.com/LagrangeInterpolatingPolynomial.html

you are right...I see I made a mistake. I put x's where I should have put c's in the denominator of the last line. No?
I actually did reading on the Lagrange polynomial and watched a video. What I discovered is it is very complicated and not very useful. It might be more useful to a math student who is at a higher level than I am and even then from what I read it is not.

 

[allegansveritatem]

I think you have the answer, and just didn't write what you meant in the last line. Compare that with the previous line, and replace some of those x's with c's ...

You don't need to know anything more than you were told in order to answer the question.

Right. I see what you are saying. The x's in the denominator should be c's. Thanks for the tip..