# Consevation of momentum help

if you have a photon with momentum $$p_\gamma$$ traveling in the +x direction which is then deflected off a free electron and now the photon has momentum $$p_\gamma'$$ and isin the +y direction.
so the components of momentum for the electron would be
p_e = $$p_\gamma'$$ in the -y direction and for the x component

$$p_ex= \sqrt{p_\gamma^2-p_\gamma'^2-p_ey^2}$$

does this seem like the correct approach to this problem?