i have a doubt in co ordinate geometry.please explain me.

Asked by  | 12th Dec, 2009, 09:43: AM

Expert Answer:

Points are collinear if the area of the triangle formed by joining the points ABC is zero

Area of triangle ABC =  1/2[1(1-11)+k(11-5)+4(5-1)] =1/2  [-10+16+6k]=1/2[6k+6]

Now for area to be zero k =-1

Answered by  | 12th Dec, 2009, 05:44: PM

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