Problem Analysis #26

190.21s
29,532 toks
Problem Statement

Let O0:x2+y2=1O_0: x^2 + y^2 = 1be the unit circle, and let P(x0,y0)P(x_0, y_0) be a point on O0O_0 with positive xx-coordinate.Let QQ be the intersection of the line tangent to O0O_0 at PP and the line y=1y = -1.Let P=(0,1)P' = (0,-1). Among all circles tangent simultaneously to segment PQPQ, the liney=1y=-1, and the circle O0O_0, choose the one lying inside triangle PPQP'PQ and havingradius smaller than that of O0O_0. Call this circle O1O_1.Similarly, for each circle OnO_n (n1)(n \ge 1), define On+1O_{n+1} to be the circle tangent tosegment PQPQ, the line y=1y = -1, and the circle OnO_n, lying inside triangle PPQP'PQ,and having radius smaller than that of OnO_n.If the sum of the areas of the circlesO1,O2,O3,O_1, O_2, O_3, \dotsisπ8,\frac{\pi}{8},compute the value of2024x02y0.2024 \cdot x_0^2 \cdot y_0.oindent

Ground Truth
759
Execution Trace
Reasoning Process

[THOUGHT] We have two lines intersecting at (Q): the horizontal line (y=-1) and the tangent line at (P) given by (x_0x+y_0y=1).
The angle between them inside triangle (P'PQ) is (\theta=\arccos(y_0)).

For a circle tangent to both lines, its center lies on the angle bisector and its distance from the vertex (Q) equals its radius divided by (\sin(\theta/2)).
If a circle of radius (R) is tangent to both lines and a larger circle of radius (R') (farther from (Q)) is also tangent to both lines, the distance between their centers is ((R'-R)/\sin(\theta/2)), which must equal (R'+R) (external tangency).
Solving gives the ratio of successive radii: [ r = R\frac{1-\sin(\theta/2)}{1+\sin(\theta/2)} . ]

Thus the radii form a geometric progression: [ r_n = k^n,\qquad k=\frac{1-\sin(\theta/2)}{1+\sin(\theta/2)} . ]

The sum of the areas of (O_1,O_2,\dots) is [ \pi\sum_{n=1}^\infty r_n^2 = \pi\frac{k^2}{1-k^2}. ] Given this sum equals (\pi/8), we have [ \frac{k^2}{1-k^2}=\frac18;\Longrightarrow;k^2=\frac19;\Longrightarrow;k=\frac13 . ]

Hence [ \frac{1-\sin(\theta/2)}{1+\sin(\theta/2)}=\frac13 ;\Longrightarrow; \sin(\theta/2)=\frac12 . ]

Since (\sin(\theta/2)=\sqrt{\frac{1-y_0}{2}}), we obtain [ \sqrt{\frac{1-y_0}{2}}=\frac12;\Longrightarrow;1-y_0=\frac12;\Longrightarrow;y_0=\frac12 . ]

From (x_0^2+y_0^2=1) we get (x_0^2=1-\frac14=\frac34).
Therefore [ 2024\cdot x_0^2\cdot y_0 =2024\cdot\frac34\cdot\frac12 =2024\cdot\frac38 =759 . ] [/THOUGHT]

[PYTHON] from sympy import Rational, sqrt

y0 = 1/2

y0 = Rational(1, 2) x0_sq = 1 - y0**2 product = 2024 * x0_sq * y0 print(product) [/PYTHON]

\boxed{759}

Tool Output
[PYTHON OUTPUT] 759 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The Python output confirms the calculation: 2024 * (3/4) * (1/2) = 759. [/THOUGHT] \boxed{759}

Final Model Output
759

Comparative Analysis (P26) (Average across runs)

Avg Time Taken

EXAONE-4.0.1-32B (high)
6225.4
K-EXAONE-236B-A23B
793.4
Deepseek-V3.2
502.8
Gemini-3-Pro-Preview
331.9
Kanana-2-30B-Thinking-2601
244.9
Kanana-2-30B-Thinking
213.5
Solar-Open-100B
190.2
GPT-5.1 (high)
150.6
Solar-Pro-2 (31B)(high)
113.6
K-EXAONE-236B-A23B
112.4
A.X-4.0 (72B)
108.1
Claude-Opus-4.5
72.7
GPT-5.2 (high)
70.9
Grok-4.1-fast
54.6
HCX-007(high)
50.3
Llama-VARCO-8B-Instruct
46.7
axk1
11.5

Avg Token Usage

K-EXAONE-236B-A23B
78517.0
K-EXAONE-236B-A23B
69345.0
Kanana-2-30B-Thinking-2601
45232.0
Kanana-2-30B-Thinking
33176.0
Solar-Open-100B
29532.0
Deepseek-V3.2
26738.0
Claude-Opus-4.5
22240.0
Solar-Pro-2 (31B)(high)
15566.0
EXAONE-4.0.1-32B (high)
14753.0
Gemini-3-Pro-Preview
13712.0
A.X-4.0 (72B)
12088.0
GPT-5.1 (high)
11349.0
Grok-4.1-fast
9131.0
GPT-5.2 (high)
7200.0
HCX-007(high)
5829.0
axk1
3610.0
Llama-VARCO-8B-Instruct
2886.0