Show that the lines 
and 
are coplanar.
Show that the lines 
and 
are coplanar ?
……(1)
……(2)
a1 = 4, b1 = 4, c1 = – 5
a2 = 7, b2 = 1, c2 = 3
x1 = 5, y1 = 7, z1 = – 3
x2 = 8, y2 = 4, z2 = 5
the condition for two line to be coplanar,
= 0
= 
= 
= 3(12 + 5) + 3(12 + 35) + 8(4 – 28)
= 3 × 17 + 3 × 47 + 8 × (–24)
= 51 + 141 – 192
= 192 – 192
= 0
The lines are coplanar to each other .
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