Question

Determine whether the given point is collinear.

P(1, 2), Q`(2, 8/5)`, R`(3, 6/5)`

Answer 1

\[P\left( 1, 2 \right), Q\left( 2, \frac{8}{5} \right), R\left( 3, \frac{6}{5} \right)\]

Slope of PQ = \[\frac{\frac{8}{5} - 2}{2 - 1} = \frac{\frac{- 2}{5}}{1} = \frac{- 2}{5}\]

Slope of QR = \[\frac{\frac{6}{5} - \frac{8}{5}}{3 - 2} = \frac{\frac{- 2}{5}}{1} = \frac{- 2}{5}\]

So, the slope of PQ = the slope of QR. 

Point Q lies on both the lines.

Hence, the given points are collinear.