" 13.दर्शाइए कि दिक्-कोखाइत "(12)/(13),(-3)/(13),(-4)/(13);(4)/(13),(12)/(13),(3)/(13);(3)/(13),(-4)/(13),(12)/(13)" वाली तीन रेखाँ परस्पर लंबवत् हैं। "quad " [NCERT] "

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

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

(2/13)^(4/3)div(2/13)^(5/3)

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

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.

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 .

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

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