# Can I decompose the Lagrange interpolating polynomial of the sum of 2 functions into 2 separate Lagrange polynomials? [closed]

For example:L[x0,x1,...,xn;f+g]=?=L[x0,x1,...,xn;f] + L[x0,x1,...,xn;g] where f and g are ordinary functions, not neccessarily polynomials......

## closed as unclear what you're asking by TheSimpliFire, i. m. soloveichik, Chris Godsil, José Carlos Santos, Mohammad Riazi-KermaniFeb 20 '18 at 0:03

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If $L[x_0, \ldots, x_n; f]$ means a polynomial of degree $\le n$ that has the same values as $f$ at $x_0, \ldots, x_n$, then yes, this is true.
• $f$ is already a polynomial of degree $n$, so its interpolating polynomial is itself. – Robert Israel Feb 19 '18 at 20:32