cos−1(326)\cos ^{-1}\left(\frac{3}{\sqrt{26}}\right)cos−1(263)
cos−1(−426)\cos ^{-1}\left(\frac{-4}{\sqrt{26}}\right)cos−1(26−4)
cos−1(426)\cos ^{-1}\left(\frac{4}{\sqrt{26}}\right)cos−1(264)
cos−1(126)\cos ^{-1}\left(\frac{1}{\sqrt{26}}\right)cos−1(261)