Question

Using Lagrange’s formula find y(11) from the following table

x	6	7	10	32
y	13	14	15	17

Answer 1

x₀ = 6, y₀ = 13 

x₁ = 7, y₁ = 14 

x₂ = 10, y₂ = 15 

x₃ = 12, y₃ = 17 

x = 11

Using Lagrange's formula,

y = 2.1666 - 4.6666 + 12.5 + 5.6666

y = 15.6666