Functions Involving Parameters, Vectors, and Matrices

If a circle has parametric equations $x = 5 \\cos(\\theta)$ and $y = 5 \\sin(\\theta)$, what is its radius?

If a particle moves along the path described by parametric equations $x = (10 - \\sin t)$, $y = (5 \\cos t)$, at what time(s) during $0 \\leq t < 6\\pi$ does its velocity have both positive components?

Which set of parametric equations represents a line passing through the origin with slope m?

Which of the following equations represents a line tangent to the circle defined by parametric equations $x(t) = r \\cos(t)$, $y(t) = r \\sin(t)$, where $t$ is measured in radians?

What type of discontinuity is represented by a hole in a graph of a function?

What is the parametric equation for a circle with radius 5 centered at the origin?

If a line is defined parametrically by $x = at + b$ and $y = ct + d$, what must be true for it to be horizontal?

Which set of parametric equations represents a line passing through (0,0) and (1,1)?

If the line described by parametric equations $x = 1 + 2t$ and $y = -3t$ intersects a circle with center at $(1,0)$, what is one possible radius of this circle?

Which set of parametric equations corresponds to a horizontal line at y = -3?