दर्शाइए कि दिक्-कोसाइन `12/13,-3/13.-4/13, 4/13,12/13,3/13,3/13,-4/13,12/13` वाली तीन रेखाएं परस्पर लंबवत है।

3/13-2/13+5/13 =

4/13+9/13+2/13=-/13

3/13+7/13+1/13

4/13 + 9/13 + 2/13 = ?/13

Show that the three lines with direction cosines 12/13,(-3)/13,(-4)/13 , 4/13,12/13,3/13 , 3/13, (-4)/13,12/13 , are mutually perpendicular .

Show that the three lines with direction cosines 12/13,-3/13,-4/13,4/13,12/13,3/13,3/13,-4/13,12/13 are mutually perpendicular.

Show that the three lines with direction cosines 12/13, -3/13, -4/13, 4/13, 12/13, 3/13, 3/13, -4/13, 12/13 are mutually perpendicular.

13^3-13^2=

Show that the three lines with direction cosines (12)/13, (-3)/13, (-4)/13 ;(4)/13, (12)/13, (3)/13; (3)/13, (-4)/13, (12)/13 are mutually perpendicular.

|(11,12,13),(12, 13, 14),(13, 14, 15)|=