Question

A positron undergoes a displacement ∆r= 2i -3j+6k, ending with the position vector r= 3j-4k, in meters. what was the positron's initial position​

Answer 1

$

\Delta{r}=2i-3j+6k \\

r_f = 3j-4k \\

\Delta{r}=r_f-r_0\Longrightarrow2i-3j+6k=3j-4k-r_0 \\

r_0=2i-3j+6k+3j-4k=\boxed{2i+6j+10k}

$