Answer
$ \lt 0,0, -2\sqrt {10} \gt $ or, any vector of the form.
Work Step by Step
$comp_ab=\frac {a \cdot b}{|a|}=2$
$\frac{3x-z}{\sqrt {10}}=2$
$3x-z = 2\sqrt {10}$
Let $x=0,y-0$ then $3(0)-z=2\sqrt {10}$
$z= -2\sqrt {10}$
Hence, the possible solutions are: $ \lt 0,0, -2\sqrt {10} \gt $ or, any vector of the form.