Identify the given force vector f and position vector r.

The force vector is $\mathbf{f} = 3\mathbf{i} + 2\mathbf{j} - 6\mathbf{k}$.
The position vector is $\mathbf{r} = 4\mathbf{i} + 5\mathbf{j} + 4\mathbf{k}$.

The moment of force $\mathbf{M}$ (or torque) about a position is given by the cross product of the position vector $\mathbf{r}$ and the force vector $\mathbf{f}$:

The cross product of two vectors $\mathbf{A} = A_x\mathbf{i} + A_y\mathbf{j} + A_z\mathbf{k}$ and $\mathbf{B} = B_x\mathbf{i} + B_y\mathbf{j} + B_z\mathbf{k}$ is given by the determinant:

Substitute the components of $\mathbf{r}$ and $\mathbf{f}$:
$A_x = 4, A_y = 5, A_z = 4$
$B_x = 3, B_y = 2, B_z = -6$

For the $\mathbf{i}$ component:

For the $\mathbf{j}$ component:

For the $\mathbf{k}$ component:

The moment of force is $-38\mathbf{i} + 36\mathbf{j} - 7\mathbf{k}$.