what should be the value of the slope for the points to be collinear?

Question

anonymous · Answer

there isn't enough information here to answer... do you have anything describing the points?

anonymous · Answer

there are three points (2,4), (7,9), and (-1,1)
I need to prove that these are collinear

anonymous · Answer

In the equation of straight lines , for collinear lines m1 = m2 and C1=c2

anonymous · Answer

@Devanshi, In your reply also, u can see m1=m2

anonymous · Answer

@Devanshi u better prove in graphical way....

anonymous · Answer

ok

anonymous · Answer

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anonymous · Answer

They are collinear if the slope between (-1,1) and (2,4) is the same as the slope between (2,4) and (7,9)

anonymous · Answer

hmmm thanks :)

anonymous · Answer

did that help?  can you find the slopes between each pair of points?

anonymous · Answer

yeah all are coming same and hence collinear

anonymous · Answer

Great :)  You wouldn't have to draw the diagram if you can just think of it... pick any 2 points and find slope... pick any 2nd pair of points and find slope.  If slope is equal, they are collinear.