Why do you doubt? Did you make any errors deliberately?
You seem to have this unit. Move on to the next one.
By the way, very clean and very readable. Keep up the good notation!
Question:
Determine if the lines passing through the given pairs of points are parallel, perpendicular or intersect obliquely.
(a) , and ,
(b) , and ,
Attempt:
(a)
Slope of : ,
Slope of : ,
The lines are perpendicular to each other. We can prove it by using .
(b)
Slope of : ,
Slope of : ,
It is an intersect obliquely.
Are my answers correct?