The vectors p q satisfy the system of equations 2 p + q = a , p +2 q = b and the angle…

The vectors \(\overrightarrow{\mathrm{p}} \& \overrightarrow{\mathrm{q}}\) satisfy the system of equations \(2 \vec{p}+\vec{q}=\vec{a}, \vec{p}+2 \vec{q}=\vec{b}\) and the angle between \(\overrightarrow{\mathrm{p}} \& \overrightarrow{\mathrm{q}}\) is θ. If it is known that in the rectangular system of
co-ordinates the vectors \(\overrightarrow{\mathrm{a}} \& \overrightarrow{\mathrm{~b}}\) have the forms \(\stackrel{\rightharpoonup}{\mathrm{a}}\)= (1, 1) & \(\overrightarrow{\mathrm{b}}\)= (1, –1) then cos θ =