Prove the Second-Order Formula for the Fourth Derivative

imsdal

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Hello there!

I'm having some issues with understanding how to prove this equation. Any tips or solution would really help me out!

. . .f(iv)(x)=f(x2h)4f(xh)+6f(x)4f(x+h)+f(x+2h)h4+O(h2)\displaystyle f^{(iv)}(x)\, =\, \dfrac{f(x\, -\, 2h)\, -\, 4f(x\, -\, h)\, +\, 6f(x)\, -\, 4f(x\, +\, h)\, +\, f(x\, +\, 2h)}{h^4}\, +\, O(h^2)

In advance, thanks for the help!
emoticon-0139-bow.gif


BR,
imsda
 
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Hello there!

I'm having some issues with understanding how to prove this equation. Any tips or solution would really help me out!

. . .f(iv)(x)=f(x2h)4f(xh)+6f(x)4f(x+h)+f(x+2h)h4+O(h2)\displaystyle f^{(iv)}(x)\, =\, \dfrac{f(x\, -\, 2h)\, -\, 4f(x\, -\, h)\, +\, 6f(x)\, -\, 4f(x\, +\, h)\, +\, f(x\, +\, 2h)}{h^4}\, +\, O(h^2)

In advance, thanks for the help!
emoticon-0139-bow.gif


BR,
imsda

Can you prove the equivalent form for the second derivative:

d2ydx2 = y(x+h)2y(x)+y(xh)h2\displaystyle \frac{d^2y}{dx^2} \ = \ \dfrac{y(x+h)-2y(x)+y(x-h)}{h^2}
 
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