What is the span of three vectors in 3D space when the third vector pokes out of the plane?
Conditions
- The first two vectors span a plane in 3D space.
- The third vector is not on that plane (it pokes out at an angle).
- The scalars , , and vary freely.
Reasoning, step by step
- Start with two vectors that span a 2D plane in 3D space.
- Introduce a third vector that points outside this plane.
- Scale the third vector to slide the 2D plane up and down.
- Allow all three scalars to vary freely in the combination .
- Conclude that the span encompasses the entire 3D volume.
Example
With three freely varying scalars (), the span encompasses every conceivable point in 3D volume.
Common misconceptions
- Believing the span remains a 2D plane.
- Thinking the third vector must be orthogonal to the plane to expand the span.
Watch the explanation
Connected concepts
Explore next
Related questions
In linear algebra, a coordinate pair like is viewed not just as a static location, but as scaling factors. The first number scales the horizontal unit vector , and the second scales the vertical unit vector .
Conditions: Working within a standard 2D Cartesian coordinate system; Using the standard unit basis vectors and
To form a basis, a set of vectors must be both linearly independent and span the target space. Linear independence means each vector contributes a brand-new dimension that cannot be recreated by the others.
Conditions: The vectors belong to the target vector space; The set is minimal (no redundant vectors)
A basis is a set of linearly independent vectors that span the target space. Each vector in the basis contributes a brand-new dimension, ensuring no redundancy, while collectively they can reach every conceivable point in the space.
Conditions: The set of vectors must be linearly independent.; The set of vectors must span the target space.
The video reinterprets a coordinate pair like not merely as a static location on a grid, but as dynamic scaling factors. The first number scales the horizontal unit basis vector , and the second number scales the vertical unit basis vector .
Conditions: Working in a standard 2D Cartesian coordinate system.; Understanding and as the standard unit basis vectors.
Answers are generated from source material and independently checked. Consult the original video or creator if something is unclear.