Question

Plot the following points and check whether they are collinear or not:
$(2,3),(3,2),(1,-5)$

Answer 1

Let's assume they are collinear as shown above in the figure:

$\therefore$ the slope of two points forming lines has to be equal.

$SlopeofAB=\left(\frac{2-3}{3-2}\right)=\left(\frac{-1}{1}\right)=-1SlopeofBC=\left(\frac{-5-2}{1-3}\right)=\left(\frac{-7}{-2}\right)=\left(\frac{7}{2}\right)asslopeisnotequal,hencegivenpointsarenotcollinear.$

And, our assumption is wrong.