What is the slope of the line passing through the following points: # (4,7) , (5,1)#?
Slope of a non-vertical line passing thro. two points (a,b) & (c,d) is defined by the ratio
Slope of a vertical line is undefined.
How can we identify a vertical line thro. given points? It is simple : All those given points will have y-co-ordinates same! Observe that this is not the case in our example, so the slope is defined.