always
A line contains at least 2 points.
{| |- | A line is defined by naming at least two points. It contains an infinite number of points, but two have to be identified. A line can also be defined by a single point and a direction. |}
The nucleus of an atom always contains at least 1 proton. It almost always contains at least 1 neutron as well.
YES. The intersection of two planes always makes a line. A line is at least two points.
A plane contains at least three non-collinear points. While two points can define a line, three points are necessary to establish a plane since they must not all lie on the same straight line. Therefore, the minimum requirement for defining a plane is three distinct points.
The answer will depend on the relative positions of the points.
You should always use the vertex and at least two points to graph each quadratic equation. A good choice for two points are the intercepts of the quadratic equation.
If you are given a plane, you can always find and number of points that are not in that plane but, given anythree points there is always at least one plane that goes through all three.
Sometimes, not always.
A three-dimensional space contains at least four noncoplanar points. An example of this is the vertices of a tetrahedron, which consists of four points that do not lie in the same plane. This arrangement ensures that the points span three dimensions, demonstrating their noncoplanarity. Other examples include points in a cube or the corners of a pyramid.
2 lines, I believe.
Wikipedia states that it will not always, but it should at least sometimes.