How do i find the length of a projection of a vector A=3x+y+2z on the xy plane?

and how do i find the unit vector in the xy plane that is perpendiculer to vector A?

To know

To find the length of the projection of vector A on the xy plane, you first need to understand that the projection of a vector onto a plane can be obtained by discarding its component perpendicular to the plane.

The xy plane can be represented by the equation z = 0, so to find the projection of vector A on the xy plane, we need to eliminate the z-component of vector A.

First, let's determine the z-component of vector A, which is 2z. Since we want to discard this component, we set z = 0:

Vector A' = 3x + y + 2(0)
= 3x + y

Now, the length of the projection Onto the xy plane can be found using the formula for the magnitude (length) of a vector. The magnitude of vector A' is given by:

|A'| = sqrt((3x)^2 + y^2)

So, the length of the projection of vector A on the xy plane is sqrt((3x)^2 + y^2).

Now, to find the unit vector in the xy plane that is perpendicular to vector A, we can determine the normal vector of the xy plane.

A normal vector of the xy plane is given by vector N = (0, 0, 1) since the xy plane is parallel to the x and y axes.

To obtain a unit vector perpendicular to vector A, we can take the cross product of vector A and the normal vector of the xy plane:

Vector B = A x N

Vector B will be perpendicular to both vector A and the xy plane. To find the unit vector in the xy plane that is perpendicular to vector A, we divide Vector B by its magnitude:

Unit Vector B = Vector B / |B|

So, by performing the cross product and normalizing the resulting vector, you can obtain the unit vector in the xy plane that is perpendicular to vector A.