From General Multivariable Taylor Series, Then, for a given partial derivative, , we can locate it from the given vector , we know that: , so we use algebra to find the original partial derivative
From General Multivariable Taylor Series, f(x)∼∑α=1kα!∂xα∂αf(x0)xα Then, for a given partial derivative, ∂xn∂nf, we can locate it from the given vector x0, we know that: a!∂xα∂αf(x0)xa=_, so we use algebra to find the original partial derivative