If \( \tan \left(\frac{\pi}{9}\right), x, \tan \left(\frac{7 \pi}{18}\right) \) are in A.P. and \( \tan \left(\frac{\pi}…

If \( \tan \left(\frac{\pi}{9}\right), x, \tan \left(\frac{7 \pi}{18}\right) \) are in A.P. and \( \tan \left(\frac{\pi}{9}\right) , y, \tan \left(\frac{5 \pi}{18}\right) \) are also in A.P. Then, \( |x-2 y|= \)

[JEE Main 2021, 27 Jul (Shift 2)]