Answer:
to check the point collinear or not the give point is equal to zero..
Explanation:
here
x1=3, y1=4 ,x2= 3 ,y2=7 ,X3= 3 ,y3=9
now
1/2 [x1(y2-y3 ) + x2 (y3-y1 ) +x3 (y1 -y2) ]
= 1/2 [ 3 ( 7-9 ) + 3 ( 9- 4) + 3 ( 4-7 )
= 1/2 [ -6+ 15 -9 ]
= 1/2 [ 0]
= 0
hence the given point is collinear.
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