दर्शाइए कि दिक्-कोसाइन `(12)/(13), (-3)/(13), (-4)/(13) , (4)/(13), ( 12)/(13), (3)/(13) , (3)/(13), (-4)/(13), (12)/(13) ` वाली तीन रेखाएँ परस्पर लंबवत है |

(-4)/(13)+0=0+(-4)/(13)

(9)/(13)+(-8)/(13)+(4)/(3)+(-5)/(8)

Check if lines with direction-cosines : lt (12)/(13) , - (3)/(13) , - (4)/(13) gt , lt (4)/(13) , (12)/(13), (3)/(13) gt , lt (3)/(13) , (4)/(13) , (12)/(13) gt are mutually perpendicular .

Find : a. 4 (5)/(13)- 3 (7)/(13) + 2 (8)/(13)

Find: ((-8))/(13)+((-4))/(13)

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

((12)/(17)times(12)/(17)-(13)/(34)times(13)/(34))/((12)/(17)+(13)/(34))

Evaluate: (-3)/(13)+((-5)/(13))

Solve : 4/(13)+2/(13)+1/(13)

Solve : 4/(13)+2/(13)+1/(13)