일반물리학 1 — Motion in Two and Three Dimensions: Problem 3

3 An elementary particle is subjected to a displacement of $\Delta \vec{r} = 2.0\hat{i} - 4.0\hat{j} + 8.0\hat{k}$, ending with the position vector $\vec{r} = 4.0\hat{j} - 5.0\hat{k}$, in meters. What was the particle’s initial position vector?