Problem Analysis #0

30.25s
6,632 toks
Problem Statement

Consider the curve CC given in polar coordinates byr=2+cosθ(0θ2π),r = 2 + \cos\theta \qquad (0 \le \theta \le 2\pi),with the origin OO as the pole and the positive xx–axis as the initial line.

  • [(1)] Compute the area of the region enclosed by the curve CC.
  • [(2)] At the point (r,θ)=(4+22,π4), (r,\theta)=\left(\frac{4+\sqrt{2}}{2},\,\frac{\pi}{4}\right), find the slope of the tangent line to the curve CC in the xyxy–coordinate plane. Let aa be the value obtained in part (1). Express the answer from part (2) in the formb+c,b + \sqrt{c},where bb and cc are integers, and let those integers be the definitions of bb and cc. Using these values of aa, bb, and cc, computeabcπ.\frac{abc}{\pi}.\
Ground Truth
-18
Execution Trace
Reasoning Process

[THOUGHT] To solve part (1), we use the polar area formula: (1/2)∫[r² dθ] from 0 to 2π. Expanding (2 + cosθ)² and integrating term by term gives the area as 9π/2. For part (2), we compute dy/dx using the derivatives of x and y in polar coordinates. After simplifying, the slope at the given point is found to be -2 + √2, leading to b = -2 and c = 2. Finally, we compute (abc)/π using the values a = 9π/2, b = -2, and c = 2.

[PYTHON]

Part (1): Compute the area

from sympy import symbols, integrate, pi, cos

theta = symbols('theta') r = 2 + cos(theta) area_integral = integrate((r**2)/2, (theta, 0, 2*pi)) a = area_integral.evalf()

Part (2): Compute the slope of the tangent line

from sympy import sqrt, sin, cos

theta_val = pi/4 r_val = (4 + sqrt(2))/2 dr_dtheta = -sin(theta_val) numerator = dr_dtheta * sin(theta_val) + r_val * cos(theta_val) denominator = dr_dtheta * cos(theta_val) - r_val * sin(theta_val) slope = numerator / denominator slope_simplified = slope.simplify()

Extract b and c from the slope expression

b = -2 c = 2

Compute abc/pi

result = (a * b * c) / pi print(f"a = {a}, slope = {slope_simplified}, b = {b}, c = {c}, result = {result}")

Since the symbolic computation might not simplify directly, we verify numerically

a_num = 9 * pi / 2 b_num = -2 c_num = 2 result_num = (a_num * b_num * c_num) / pi print(f"Numerical result: {result_num}") [/PYTHON]

Tool Output
[PYTHON OUTPUT] a = 14.1371669411541, slope = -2 + sqrt(2), b = -2, c = 2, result = -56.5486677646163/pi Numerical result: -18 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The Python output confirms that the numerical value of (\frac{abc}{\pi}) is (-18). This is derived from (a = \frac{9\pi}{2}), (b = -2), and (c = 2), and the calculation (\frac{abc}{\pi} = -18). The symbolic simplification of the slope as (-2 + \sqrt{2}) also aligns with the given form (b + \sqrt{c}) where (b = -2) and (c = 2). Thus, the final result is (-18).

\boxed{-18}

Final Model Output
-18

Comparative Analysis (P0) (Average across runs)

Avg Time Taken

Gemini-3-Pro-Preview
316.3
Deepseek-V3.2
81.3
Llama-VARCO-8B-Instruct
49.3
GPT-5.1 (high)
38.4
HCX-007(high)
36.4
Solar-Pro-2 (31B)(high)
30.2
Grok-4.1-fast
21.1
Claude-Opus-4.5
18.0
A.X-4.0 (72B)
16.6
EXAONE-4.0.1-32B (high)
6.7

Avg Token Usage

Gemini-3-Pro-Preview
12238.0
Deepseek-V3.2
7244.0
Solar-Pro-2 (31B)(high)
6632.0
HCX-007(high)
6397.0
Grok-4.1-fast
6290.0
GPT-5.1 (high)
4822.0
Claude-Opus-4.5
4528.0
Llama-VARCO-8B-Instruct
4316.0
EXAONE-4.0.1-32B (high)
4306.0
A.X-4.0 (72B)
3605.0