Which parametric equations describe a circle with its center at the origin and a radius of 7 for $0 \leq t \leq 2 \pi ?$
A) x=7 cos t and y=7 sin t
B) x=7 sin t and y=7 sin t
C) x=cos 7 t and y=sin 7 t
D) $x=\frac{1}{7} \cos t \text { and } y=\frac{1}{7} \sin t$
E) x=49 cos t and y=49 sin t

Question

Which parametric equations describe a circle with its center at the origin and a radius of 7 for $0 \leq t \leq 2 \pi ?$
A)  x=7 cos t  and  y=7 sin t 
B)  x=7 sin t  and  y=7 sin t 
C)  x=cos 7 t  and  y=sin 7 t 
D) $x=\frac{1}{7} \cos t \text { and } y=\frac{1}{7} \sin t$
E)  x=49 cos t  and  y=49 sin t

Quizplus · Accepted Answer

The parametric equations $x = 7\cos(t)$ and $y = 7\sin(t)$ describe a circle with a radius of 7 and its center at the origin, as they scale the unit circle ($x = \cos(t), y = \sin(t)$) by a factor of 7.

Which Parametric Equations Describe a Circle with Its Center at the Origin