Problem Analysis #41

24.38s
4,639 toks
Problem Statement

Let CC be the curve given parametrically byx=e4t(1+sin2πt),y=e4t(13cos2πt).x = e^{4t}(1 + \sin^2 \pi t), \qquad y = e^{4t}(1 - 3\cos^2 \pi t).Let PP be the point where CC intersects the line y=3x5ey = 3x - 5e. Determine the slope of the tangent to CC at PP. [3 points]If the slope is aπbπ+c\frac{a\pi - b}{\pi + c}, compute a+b+ca+b+c.\

Ground Truth
11
Execution Trace
Reasoning Process

[THOUGHT] The intersection occurs where e^{4t} = e, so t = 1/4. Verify this and compute the slope dy/dx = (dy/dt)/(dx/dt) at t=1/4 using sympy for exact computation. [/THOUGHT] [PYTHON] import sympy as sp

t = sp.symbols('t') x = sp.exp(4t) * (1 + sp.sin(sp.pi * t)**2) y = sp.exp(4t) * (1 - 3 * sp.cos(sp.pi * t)**2)

dxdt = sp.diff(x, t) dydt = sp.diff(y, t)

slope = dydt / dxdt slope_at_t = slope.subs(t, sp.Rational(1,4))

print(slope_at_t.simplify()) print(sp.N(slope_at_t)) # numerical check [/PYTHON]

Tool Output
[PYTHON OUTPUT] (-2 + 3*pi)/(pi + 6) 0.812197419215979 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The slope is \frac{3\pi - 2}{\pi + 6}, so a=3, b=2, c=6, and a+b+c=11. [/THOUGHT] \boxed{11}

Explanation

The reasoning begins by identifying the intersection point P where the curve C intersects the line y = 3x - 5e. Substituting the parametric equations into the line equation yields e^{4t}(1 + sin²(πt)) for x and e^{4t}(1 - 3 cos²(πt)) for y, leading to e^{4t}(1 - 3 cos²(πt)) = 3 e^{4t}(1 + sin²(πt)) - 5e. Simplifying shows e^{4t} = e at t = 1/4, as the exponential factor aligns with the constant term.

Next, the slope of the tangent is computed as dy/dx = (dy/dt) / (dx/dt) evaluated at t = 1/4. The parametric derivatives are calculated using SymPy: dx/dt from differentiating x = e^{4t}(1 + sin²(πt)) and dy/dt from y = e^{4t}(1 - 3 cos²(πt)). Substituting t = 1/4 into the ratio dydt / dxdt and simplifying produces the exact expression (-2 + 3π)/(π + 6), equivalent to (3π - 2)/(π + 6).

This matches the form \frac{aπ - b}{π + c}, where a = 3, b = 2, and c = 6. Therefore, a + b + c = 3 + 2 + 6 = 11, confirming the result from the Python output.

Final Model Output
11

Comparative Analysis (P41) (Average across runs)

Avg Time Taken

Llama-VARCO-8B-Instruct
92.0
GPT-5.1 (high)
76.3
Deepseek-V3.2
73.2
Gemini-3-Pro-Preview
52.1
HCX-007(high)
44.4
Solar-Pro-2 (31B)(high)
32.2
A.X-4.0 (72B)
26.2
Grok-4.1-fast
24.4
Claude-Opus-4.5
20.1
EXAONE-4.0.1-32B (high)
5.9

Avg Token Usage

GPT-5.1 (high)
11773.0
Llama-VARCO-8B-Instruct
7592.0
Gemini-3-Pro-Preview
7354.0
Claude-Opus-4.5
7243.0
Solar-Pro-2 (31B)(high)
6628.0
Deepseek-V3.2
5861.0
HCX-007(high)
5058.0
Grok-4.1-fast
4639.0
EXAONE-4.0.1-32B (high)
3981.0
A.X-4.0 (72B)
2344.0