P ( x ) = x − x 1 x 0 − x 1 y 0 + x − x 0 x 1 − x 0 y 1 {\displaystyle P(x)={\frac {x-x_{1}}{x_{0}-x_{1}}}y_{0}+{\frac {x-x_{0}}{x_{1}-x_{0}}}y_{1}}
