Question

A(-1,-1), B(0,1), C(1,3) Determine whether the given points are collinear.

Answer 1

no the points are not collinear .

Answer 2

Solution :

Let A(-1,-1) = (x1,y1),B(0,1)=(x2,y2),

C(1,3)=(x3,y3) are vertices of

Triangle ABC.

Area of ∆ABC

=1/2|x1(y2-y3)+x2(y3-y1)+x3(y1-y2)|

=1/2|(-1)[1-3]+0[3-(-1)]+1[-1-1]|

= 1/2| (-1)(-2)+0+1(-2)|

=1/2| 2 -2 |

= 1/2 × 0

= 0

Therefore ,

Area of ∆ABC = 0,

A , B and C points are collinear.

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