Determining if 3 points lie on a straight line.

[siztem]

Ah, so this is what it's like to be deaf.

[mathadventuress]

i love the sound of your voice and the way you explain things.

[billybobultra]

lol this is the exact same question off my textbook. 
james stewart Calculus 8th ed. chapter 12.2 #11
who else?

[LifeForAiur]

I'm afraid that, although your method is correct, it does require a certain modification. You made the premise that the points go in the order of A, B, C. Where AC is ultimately a larger distance than BC or AB. This is simply not true. You must avoid that conclusion and simply calculate the possible distances of three arbitrary points and check if the smaller two distances equal to the largest distance. In this case we would check if BC equals to AC+AB. Your answer is correct, however a slight modification must have been made in the way you approached the problem. I give you the case: AB=3 BC= 1 and AC=2. Surely AC does not equal AB + BC however BC and AC do indeed equal AB. This is only a slight modification, however. The answer to this question is fundamentally the same regardless of modified method. 

[JonesyMcDanes]

Why is everyone giving this video hate? Do you really need audio to tell what's happening?

[peterlee]

I wish I could give this a "meh wobbly hand rating"

[meierjoe]

if u explain with audio it would be great 

[williamwiseman]

dude your profile pic is a drunk, how can I trust you? Great vid btw