From Mechanics

We insert \displaystyle t=0\ \text{s} in the expression for the position vector to find the point where the frisby waqs thrown from.

\displaystyle \begin{align} & \mathbf{r}=\left( 5\times 0-{{0}^{2}} \right)\mathbf{i}+\left( 7\times 0 \right)\mathbf{j}+0\mathbf{k} \\ & \\ & =-24\mathbf{i}+56\mathbf{j}+0\mathbf{k}\ \text{m} \\ \end{align}

The point where the frisby was thrown is the origin. This is obtained by putting \displaystyle t=0 in the expression for \displaystyle \mathbf{r} giving \displaystyle \mathbf{r} =0\mathbf{i}+0\mathbf{j}+0\mathbf{k}\ \text{m}.