# LaTeX Test

We interpolate points$\{(x_k,f_k)\}$ by polynomial
$P_{N-1}(x)=\sum_{j=0}^{N-1}{a_jx^j}$

Its coefficients $\{a_j\}$ are found as a solution of system of linear equations:
$\left\{ P_{N-1}(x_k) = f_k\right\},\quad k=-\frac{N-1}{2},\dots,\frac{N-1}{2}$

Code example:

def fib(n):
if n == 0:
return 0
elif n == 1:
return 1
else:
return fib(n-1) + fib(n-2)