$x_{i-2}$

$x_{i-1}$

$x_i$

$x_{i+1}$

$x_{i+2}$

${\varphi }_i\left(x\right)$

1

26

66

26

1

${{\varphi }^{\prime }}_i\left(x\right)$

5/h

50/h

−50/h

−5/h

${{\varphi }^{″}}_i\left(x\right)$

20/h²

40/h²

−120/h²

40/h²

20/h²

${{\varphi }^{‴}}_i\left(x\right)$

−60/h³

120/h³

120/h³

60/h³