Talk:Brahmagupta's interpolation formula

Blunder
The formula in the article is not right. The right formula is
 * $$ f(a)= f_r + t \frac{D_r + D_{r-1}}{2} + t^2\frac{D_{r} - D_{r-1}}{2}.$$

Or, if you want to keep the formula, you should define
 * $$D_r=f_r-f_{r-1}$$.

МетаСкептик12 (talk) 14:20, 3 June 2015 (UTC)