What does vector multiplication equal to negative one mean?

What does vector multiplication equal to negative one mean?

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Why can vector a be multiplied by vector b, i.e. equal to coordinate multiplication in addition, or equal to the angle between two vectors by cos Why can vector a be multiplied by vector b, i.e. equal to coordinate multiplication in addition, or equal to cos angle of two vectors

You pick two points on a piece of paper, mark the coordinates, connect them from the origin, and look at the map

Can vector coordinates be multiplied? I asked for multiplication. Not quantity product. If vector a=(2.3) vector b equals (4,6) (The following subtitles all represent vectors) Then, can a (a+b) be equal to (2,3)2+(2,3)(4,6) Note that ab is not a product of quantities. If this is not true, what should a (a+b) be written as? Not between a and (a+b)· Can vector coordinates be multiplied? I asked for multiplication. Not quantity product. If vector a=(2.3) vector b equals (4,6) (The following subtitles all represent vectors) Then, can a (a+b) be equal to (2,3)2+(2,3)(4,6) Note that ab is not a product of quantities. If this is not true, what should a (a+b) be written? Not between a and (a+b)· Can vector coordinates be multiplied? I'm asking for multiplication. Not quantity product. If vector a=(2.3) vector b equals (4,6) (The following subtitles all represent vectors) Then, can a (a+b) be equal to (2,3)2+(2,3)(4,6) Note that ab is not a product of quantities. If this is not true, what should a (a+b) be written as? Not between a and (a+b)·

It should be as follows: a (a+b)=a2+abcos. Where is the angle between vectors a and b. If you are satisfied, please reply.

Vector coordinate multiplication Given the plane vector a (1,2) vector b (-1,3) vector c=a-(a*b)*b, find the vector c The answer is (6,-13),

A*b=1*(-1)+2*3=5
(A*b)*b=5b=(-5,15)
A-(a*b)*b=(1-(-5),2-15)=(6,-13)
Note: vector * vector = quantity, quantity * vector = vector

How to express by coordinates after two vectors are multiplied For example, the coordinates of vector a are X1, Y1, the coordinates of vector b are X2, Y2, a. b are expressed in terms of coordinates, and the result of multiplication is expressed in terms of coordinates How to express by coordinates after two vectors are multiplied For example, the coordinates of vector a are X1, Y1, the coordinates of vector b are X2, Y2, a. b are expressed in coordinates, and the result of multiplication is expressed

A (x1, y1, z1), b (x2, y2, z2)
Number product (dot product, inner product): a.b = x1x2+y1y2+z1z2 is equal to a value (scalar quantity);
Vector product (cross product): a ×b =| e1 e2 e3|
| X1 y1 z1|(1)
| X2 y2 z2|
E1, e2, e3 are the three unit vectors of the axis of the OXYZ coordinate system. The product of the vectors is represented by a determinant (1) whose direction is perpendicular to the ab plane (right-hand rule).

Why is it that if the moduli of two vectors are equal, then the two vectors are parallel

Perhaps the questioner is wrong, and it should be said that the two vectors are parallel.
Vectors are directional (and, of course, length), which need not be explained, because the vectors are equal, which means that their two factors (direction and modulus) are equal, and since the directions are equal, they are naturally parallel.
PS: mold is only length

Perhaps the questioner is wrong, and it should be said that the two vectors are parallel if the vectors are equal.
Vectors are directional (and, of course, length), which need not be explained, because the vectors are equal, which means that their two factors (direction and modulus) are equal, and since the directions are equal, they are naturally parallel.
PS: modulus is only length