# Representing an interpolating function

I just want to figure out how to "represent" or to inject an interpolating function into a numerical calculation. So, suppose i have an interpolating function $$int$$ and then i want to use NDSolve or Rationalize or any numerical operations involving $$int$$. How do I implement the routine. I have expanded this function using Series and it gave me the output $$1+2x+..$$ as i desire. But if I do any operation involving only the interpolating function itself, the output includes the interpolating box. How do i properly represent an interpolating function in an operation without the interpolating box appearing in the output? Thanks

Attached is the operation where TPint is the interpolating function.

• Can you give example code where you couldn't get it to work? – J. M. will be back soon Oct 17 '18 at 2:43
• E.g. NIntegrate[int[x], {x, 0, 1}] works fine for me.....So does NDSolve[{y'[x] == int[x], y[0] == -1}, y, {x, 0, 1}].... – Michael E2 Oct 17 '18 at 3:02
• I have edited my question. Please see attached figure. Thanks – user583893 Oct 17 '18 at 3:06
• It should maybe be TPint[x] or something like it; you're supposed to be applying an interpolating function to something. Otherwise it's like writing Sqrt[1 - (b/Sin)^(1 - q)]. – J. M. will be back soon Oct 17 '18 at 3:10
• Or maybe series expanding will do the thing, I guess? I just want to manipulate the interpolating function so as to use it in numerical calculations. – user583893 Oct 17 '18 at 3:37