Problem Analysis #28

29.86s
7,316 toks
Problem Statement

Consider two points A(5,0)A(5,0) and B(5,0)B(-5,0) in the coordinate plane. A point CC and a point PP in the same plane satisfy the following conditions:(i)AC=6,(ii)A point P lies on segment AC,(iii)BP+CP=8.\begin{aligned}\text{(i)} &\quad \overline{\text{AC}} = 6,\\\text{(ii)} &\quad \text{A point P lies on segment } AC,\\\text{(iii)} &\quad \overline{\text{BP}} + \overline{\text{CP}} = 8.\end{aligned}Let A=θ\angle A = \theta in triangle ABCABC, and let the area of triangle BCPBCP be denoted by f(θ)f(\theta).For an angle β\beta satisfyingcosβ=45,0<β<π2,\cos \beta = \frac{4}{5}, \qquad 0 < \beta < \frac{\pi}{2},assume thatf(β)=pq,f'(\beta) = -\frac{p}{q},where pp and qq are relatively prime positive integers.(Also, point CC does not lie on segment ABAB, and point PP is distinct from point CC.)Find the value ofp+q2.p + q^{2}.oindent

Ground Truth
721
Execution Trace
Reasoning Process

[THOUGHT] The position of C is (5 - 6cos(θ), 6sin(θ)). Parameter s = 4 / (1 + 5cos(θ)). The area f(θ) = 30 * sin(θ) * (1 - s) = 30 * sin(θ) * (5cos(θ) - 3) / (1 + 5*cos(θ)). To verify f'(β) where cos(β) = 4/5, sin(β) = 3/5, use sympy to compute the derivative and evaluate. [/THOUGHT] [PYTHON] import sympy as sp

theta = sp.symbols('theta') c = sp.cos(theta) s = sp.sin(theta) f = 30 * s * (5c - 3) / (1 + 5c)

df = sp.diff(f, theta) beta_val = df.subs({c: 4/5, s: 3/5}) print(beta_val) print(sp.simplify(beta_val)) [/PYTHON]

Tool Output
[PYTHON OUTPUT] -3.84000000000000 -3.84000000000000 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The Python output -3.84 is -96/25, so p=96, q=25, p + q^2 = 96 + 625 = 721. [/THOUGHT] \boxed{721}

Explanation

The provided AI thought derived the function f(θ) = 30 * sin(θ) * (5cos(θ) - 3) / (1 + 5cos(θ)) based on the geometric setup: point C at (5 - 6cos(θ), 6sin(θ)), parameter s = 4 / (1 + 5*cos(θ)) for point P on AC, and area of triangle BCP as 30 * sin(θ) * (1 - s).

The derivative f'(θ) was computed using SymPy and evaluated at β where cos(β) = 4/5 and sin(β) = 3/5, yielding -3.84000000000000.

This numerical value equals -96/25 exactly, as 96 ÷ 25 = 3.84. Here, 96 and 25 are coprime positive integers, satisfying f'(β) = -p/q with p = 96 and q = 25.

Thus, p + q² = 96 + 25² = 96 + 625 = 721.

Final Model Output
721

Comparative Analysis (P28) (Average across runs)

Avg Time Taken

Deepseek-V3.2
508.6
EXAONE-4.0.1-32B (high)
214.8
Solar-Pro-2 (31B)(high)
190.5
Gemini-3-Pro-Preview
129.8
GPT-5.1 (high)
69.8
Claude-Opus-4.5
68.5
A.X-4.0 (72B)
56.7
HCX-007(high)
37.4
Llama-VARCO-8B-Instruct
35.0
Grok-4.1-fast
29.9

Avg Token Usage

Claude-Opus-4.5
31624.0
EXAONE-4.0.1-32B (high)
17509.0
Solar-Pro-2 (31B)(high)
11892.0
Deepseek-V3.2
9057.0
Grok-4.1-fast
7316.0
GPT-5.1 (high)
7155.0
Gemini-3-Pro-Preview
6414.0
HCX-007(high)
4909.0
A.X-4.0 (72B)
4067.0
Llama-VARCO-8B-Instruct
1224.0