Introduction:



Interpolationis the process of defining a function that takes on specified values at specified points. Interpolation as used here is different to "smoothing"; the techniques discussed here have the characteristic that the estimated curve passes through all the given points.




Approximation
is the process of defining a function that take on approximate points or near about a fix point. .In approximation, we measure the deviation of the given function f (x) from the approximating function P(x) for all values of aclose interval of a subset.