Question

Dot product, determine whether the three points are vertices of a triangle A=(-2,3), B=(3,1), C=(-4,-1)

Answer 1

Dot product is also known as scalar product

Answer 2

How did you find the vertices with the dot product?

Answer 3

the question gives you the verticies. So i made a small plot to show approximately where they would be.

Answer 4

What is the dot product equation?

Answer 5

for two points it is

A = (x1, y1) B = (x2, y2)

x1 * x2 + y1 * y2

it is safe to assume that with all three points, you would multiply all three x values.

so it would look something like this
A=(-2,3), B=(3,1), C=(-4,-1)

Dot Product = -2*3*-4 + 3*1*-1

Answer 6

24 - 3 = 21

Answer 7

where did you get 24-3 from

Answer 8

im not too sure where to go with this. its combining the dot product that we found.

Answer 9

I was thinking maybe we need to put the current vertices into vectors since we are looking for the dot product.

Answer 10

lets do our dot products with only two points at a time

A=(-2,3), B=(3,1), C=(-4,-1)

A dot B = -2 * 3 + 3 * 1 = -3
A dot C = -4*-2 + 3*-1 = 5
B dot C = -4 * 3 + 1 * -1 = -13

AB = -3,
AC = 5
BC = -13

Answer 11

I got that too, but when I worked out into a^2+b^2=c^2 it doesn't equal a right triangle

Answer 12

not everything has to be a right triangle. this is not a triangle. The longest side is longer than the sum of the two smaller sides, so the triangle would not occur.