dot product is a.b = |a||b|cosQ where Q is the angle
Also if two vectors are considered orthogonal if their dot product is zero (a.b=0)
vector product is a*b = |a||b|sinQn where n is a unit vector perpendicular to the plane containing a and b.
while in a cross product if two non-zero...
I mean when i find PAB, PAC, PCB i get all of those areas as 0.
which is not equal to the area of ABC.
hence (2,2) does not fall in the triangle ABC although it is supposed to be.
ok i kinda understand werg22 area method but i still don't get the right answer.
Could someone please help me out with this
A (0,0)
B (1,5)
C (4,1)
P (2,2)
I am getting the area of ABC as 9.5
PAB+PAC+PCB=0
Technically (2,2) should be in but according to your method if it isn't...
so u mean first find the area of the triangle using the coordinate points.
and then do PAB+PAC+PCB=are of triangle using the given coordinate points.
what i don't understand is how does PAB+PAC+PCB work??
I mean AB, AC, CB can be found using distance formula but P is suppose some point...
Thanks but no not for that particular point.
I mean the coordinates can be different except the origin. (0, 0)
how do we know if we have to find the equation of line of AC or AB or BC??
ex: if the origin points are A = (0, 0)
B = (3,5)
C= (6,3)
How do we know that point (3,1) lies within or outside the triangle using mathematical formulas?
I know there is a similar topic to this somewhere in forums but i don't understand where a & b comes from.
please can anyone...