\[\dfrac{\operatorname{ce}_{m}\left(x,h^{2}\right)}{\operatorname{ce}_{m}\left(0%
,h^{2}\right)}=\dfrac{2^{m-(\ifrac{1}{2})}}{\sigma_{m}}\left(W_{m}^{+}(x)(P_{m%
}(x)-Q_{m}(x))+W_{m}^{-}(x)(P_{m}(x)+Q_{m}(x))\right),\]