$\"\"$

The initial point of a vector is $\"\"$ .

The vector has magnitude $\"\"$ .

The locus of terminal points $\"\"$ are the points that satisfy the equation $\"\"$ .

The locus of terminal points $\"\"$ are the points that lie on the circle that has a center at $\"\"$ and a radius of $\"\"$ .

Consider a vector with an initial point at the origin and a magnitude of $\"\"$ .

$\"\"$

The circle is formed by the terminal points of many vectors with this initial point and magnitude.

$\"\"$

The initial point of a vector is $\"\"$ .

The vector has magnitude $\"\"$ .

The locus of terminal points $\"\"$ are the points that satisfy the equation $\"\"$ .