\text{Let } P_1(1+\cos t,; \sin t)\text{ be a point moving on the circle with center } (1,0)\text{ and radius } 1,]Both points start at the intersection point of the two circlesand move counterclockwise along their respective circles.Assume that their speeds satisfyLet be the time when the distance between and is maximized.At this moment, the following expression:where and are relatively prime positive integers.Find the value of .oindent
[THOUGHT] We have two points: P1 = (1+cos t, sin t) on circle center (1,0) radius 1. P2 = (2 cos θ(t), 2 sin θ(t)) on circle center (0,0) radius 2. Both start at intersection (2,0) at t=0. So at t=0: P1(1+cos0, sin0) = (2,0) correct. P2(2 cos θ(0), 2 sin θ(0)) = (2,0) => cos θ(0)=1, sin θ(0)=0 => θ(0)=0. They move counterclockwise. Speeds satisfy |P1'(t)| : |P2'(t)| = 1 : 4. We need to find t = t0 when distance between P1 and P2 is maximized. At that moment, the expression sin t * 2 sin θ(t) - (1+cos t) * 2 cos θ(t) = p/q (rational). Find p+q.
First, we need to relate θ(t) and t via speed condition. Compute derivatives: P1(t) = (1+cos t, sin t) P1'(t) = (-sin t, cos t) Speed |P1'(t)| = sqrt(sin^2 t + cos^2 t) = 1. So speed of P1 is constant 1.
P2(t) = (2 cos θ(t), 2 sin θ(t)) P2'(t) = (-2 θ'(t) sin θ, 2 θ'(t) cos θ) Speed |P2'(t)| = sqrt(4 (θ')^2 sin^2 θ + 4 (θ')^2 cos^2 θ) = 2 |θ'(t)|. Given ratio |P1'| : |P2'| = 1 : 4 => 1 / (2 |θ'|) = 1/4 => 2 |θ'| = 4 => |θ'| = 2. Since both moving counterclockwise, θ'(t) positive? Let's check: At start, moving counterclockwise from (2,0). For P1, increasing t moves counterclockwise? At t=0, P1=(2,0). For small t>0, cos t decreases, sin t increases, so point moves upward and leftward, which is counterclockwise on circle centered (1,0) radius 1. Yes. For P2, counterclockwise from (2,0) means increasing θ from 0. So θ'(t) > 0. So θ'(t) = 2. Thus θ(t) = 2t + C. At t=0, θ(0)=0 => C=0. So θ(t) = 2t.
Thus P2(t) = (2 cos(2t), 2 sin(2t)).
Now distance squared between P1 and P2: D^2(t) = (1+cos t - 2 cos(2t))^2 + (sin t - 2 sin(2t))^2. We need to maximize D(t) over t in [0,2π]. Since both periodic, we can consider t in [0,2π].
We need to find t0 where D is maximum. Then compute expression: E(t) = sin t * 2 sin θ(t) - (1+cos t) * 2 cos θ(t) = 2 sin t sin(2t) - 2 (1+cos t) cos(2t). Simplify: E(t) = 2[ sin t sin(2t) - (1+cos t) cos(2t) ]. We can expand sin(2t)=2 sin t cos t, cos(2t)=cos^2 t - sin^2 t = 2 cos^2 t -1 = 1 - 2 sin^2 t. But maybe we can simplify E further: E(t) = 2[ sin t * 2 sin t cos t - (1+cos t)(cos^2 t - sin^2 t) ] = 2[ 2 sin^2 t cos t - (1+cos t)(cos^2 t - sin^2 t) ]. Alternatively, we can express E(t) in terms of dot product? Actually note that E(t) = 2[ (sin t) sin(2t) - (1+cos t) cos(2t) ] = -2[ (1+cos t) cos(2t) - sin t sin(2t) ] = -2 * something like dot product? Actually (1+cos t, sin t) dot (cos(2t), -sin(2t))? Not exactly.
Maybe we can relate E to distance? Or we can compute directly after finding t0.
We need to find t0 that maximizes D(t). Let's compute D^2(t) explicitly.
We'll use Python to compute D^2(t), find its maximum, then compute E(t0) and see if it's rational.
We'll use sympy or numeric optimization. Since we need exact rational? The expression E(t0) is given as p/q, so likely rational. So t0 might be a special angle. Let's compute D^2(t) symbolically and find critical points.
Let's do in Python. [/THOUGHT] [PYTHON] import sympy as sp
define variable
t = sp.symbols('t', real=True)
define coordinates
x1 = 1 + sp.cos(t) y1 = sp.sin(t) x2 = 2 * sp.cos(2t) y2 = 2 * sp.sin(2t)
squared distance
D2 = (x1 - x2)**2 + (y1 - y2)**2
simplify D2
D2_simplified = sp.simplify(D2) print("D^2(t) =", D2_simplified) [/PYTHON]
[THOUGHT] The squared distance simplifies to ( D^2(t) = 8\sin^2 t - 2\cos t + 2 ). To maximize distance, we can maximize ( D^2(t) ). Since ( \sin^2 t = 1 - \cos^2 t ), we can write ( D^2(t) = 8(1 - \cos^2 t) - 2\cos t + 2 = 8 - 8\cos^2 t - 2\cos t + 2 = 10 - 8\cos^2 t - 2\cos t ). Let ( u = \cos t ), then ( D^2 = 10 - 8u^2 - 2u = -8u^2 - 2u + 10 ). This is a quadratic in ( u ) with maximum at vertex since coefficient of ( u^2 ) is negative. Vertex at ( u = -\frac{b}{2a} = -\frac{-2}{2(-8)} = \frac{2}{-16} = -\frac{1}{8} ). So maximum occurs when ( \cos t = -\frac{1}{8} ). Then ( \sin^2 t = 1 - \frac{1}{64} = \frac{63}{64} ), so ( \sin t = \pm \frac{\sqrt{63}}{8} = \pm \frac{3\sqrt{7}}{8} ). Since both points move counterclockwise and start at (2,0), for maximum distance, we need to determine the correct sign of ( \sin t ). At ( t=0 ), distance is 0 (since both at same point). As ( t ) increases, distance increases. The maximum likely occurs for ( t ) in ( (0, \pi) ) where ( \sin t > 0 ). So take ( \sin t = \frac{3\sqrt{7}}{8} ).
Now compute ( E(t) = 2[ \sin t \sin(2t) - (1+\cos t) \cos(2t) ] ). Use identities: ( \sin(2t) = 2\sin t \cos t ), ( \cos(2t) = 2\cos^2 t - 1 ). Substitute ( \cos t = -\frac{1}{8} ), ( \sin t = \frac{3\sqrt{7}}{8} ).
Compute stepwise: ( \sin(2t) = 2 \cdot \frac{3\sqrt{7}}{8} \cdot \left(-\frac{1}{8}\right) = -\frac{6\sqrt{7}}{64} = -\frac{3\sqrt{7}}{32} ). ( \cos(2t) = 2 \cdot \frac{1}{64} - 1 = \frac{2}{64} - 1 = \frac{1}{32} - 1 = -\frac{31}{32} ). Now compute ( \sin t \sin(2t) = \frac{3\sqrt{7}}{8} \cdot \left(-\frac{3\sqrt{7}}{32}\right) = -\frac{9 \cdot 7}{256} = -\frac{63}{256} ). Compute ( (1+\cos t) = 1 - \frac{1}{8} = \frac{7}{8} ). Then ( (1+\cos t) \cos(2t) = \frac{7}{8} \cdot \left(-\frac{31}{32}\right) = -\frac{217}{256} ). Thus ( \sin t \sin(2t) - (1+\cos t) \cos(2t) = -\frac{63}{256} - \left(-\frac{217}{256}\right) = -\frac{63}{256} + \frac{217}{256} = \frac{154}{256} = \frac{77}{128} ). Multiply by 2: ( E(t) = 2 \cdot \frac{77}{128} = \frac{77}{64} ). So ( p/q = 77/64 ), with ( p=77, q=64 ) relatively prime. Then ( p+q = 77+64 = 141 ).
Thus final answer is 141. [/THOUGHT] \boxed{141}