Math Help - How to find the Newton Polynomial Approximation?

I need to find the Newton Polynomial Approximation for f(x) = 1/(sqrt(1-x)) on the interval [-1.5, 0.95] and to investigate which polynomial order is more sufficient for an accurate representation of the above function.

I honestly have no idea how to go about this and I tried to understand it with Wikipedia Newton polynomial - Wikipedia, the free encyclopedia but it's beyond me.

As much as I would like the answer, I would also like to understand this so any help is greatly appreciated.

PS. Wasn't sure which category this went under so I've put it here.

With an interpolation problem, it is usual to be given some number of points the problem then being to find a polynomial passing through those points. Do you have such a set or are we free to choose whatever and however many we want ?