By definition. E.g. f(x)=f(x+h)−−−−−−−−−→(1). Δf(x)=f(x+h)−f(x). Δf(x)=Ef(x)−f(x). Δf(x)=(E−1)f(x). ∴Δ=E−1.
確定! 回上一頁