
Julia S. answered 07/25/21
Calculus Made Manageable
Given the equation (x-10)2 + y2 = 25, we will need the parametrization equations for circles not centered about the origin:
x = h + rcos(θ)
y = k + rsin(θ)
in which (h,k) is the center of the circle and r is the radius. The center of our circle is at (10,0) so we plug this in for (h,k), and our radius is √25 = 5. Our equations are then
x = 10 + 5cos(θ)
y = 5sin(θ)
for all θ such that 0 ≤ θ ≤ 2π

Julia S.
I reread the problem (I think I got ahead of myself). It requests that you start at (5,0) and move clockwise for 2 theta. In order to start at theta = 0 at the point (5,0), the equation for x would be: x = 5cos(theta) This gives you a value of x = 5 for theta = 0. The original equation works only if you start at (15,0). Please try that and let me know how it goes!07/25/21
Chris N.
the answer is x=10-5cos(theta). Thanks for the help07/26/21

Julia S.
Gotcha - I apologize I couldn’t get you there.07/26/21
Chris N.
I tried that before and it says the equation for x is wrong. "Your second answer is correct, but your first answer is incorrect. The equation of a circle with radius r and center (h,k) is (x-h)^2 + (y-k)^2 = r^2. Determine the relationship between x and y in terms of theta. Use this relationship to write the equation of the circle in terms of x and theta, and then in terms of y and theta in order to find the parametric equations for the particle's motion."07/25/21