If the pair of lines $2 x^2+3 x y+y^2=0$ makes angles $\theta_1$ and $\theta_2$ with the positive direction…
If the pair of lines $2 x^2+3 x y+y^2=0$ makes angles $\theta_1$ and $\theta_2$ with the positive direction of the X-axis, then $\left|\tan \left(\theta_1-\theta_2\right)\right|=$