# Thread: Help me in numerical analysis (interpolation)

1. ## Help me in numerical analysis (interpolation)

Please, I need your help to solve these difficult problems in the interpolation from numerical analysis course

2. ## Re: Help me in numerical analysis (interpolation)

Originally Posted by Abdulla
Please, I need your help to solve these difficult problems in the interpolation from numerical analysis course
For the first you are told that P(x) is a fourth degree polynomial, so you know that the fourth differences are constant.

CB

3. ## Re: Help me in numerical analysis (interpolation)

Originally Posted by Abdulla
Please, I need your help to solve these difficult problems in the interpolation from numerical analysis course
For the second, you are being told that P(x) is a cubic and are provided with enough information to construct its value at any integer argument.

CB

4. ## Re: Help me in numerical analysis (interpolation)

Thanks,But I can't understand the idea in the first problem, can you wite it symbolically??? please help me

5. ## Re: Help me in numerical analysis (interpolation)

Originally Posted by Abdulla
Thanks,But I can't understand the idea in the first problem, can you wite it symbolically??? please help me
There are at least two approaches, the first is to reconstruct the polynomial from the differences, and the second is to just reconstruct the differences table using:

$\displaystyle \Delta^{n-1}P(n+1)=\Delta^{n}P(n)+\Delta^{n-1}P(n)$

CB