Problem Analysis #19

43.25s
6,621 toks
Problem Statement

For all x>0x > 0, let y1(x)y_1(x), y2(x)y_2(x), and y3(x)y_3(x) be the functions satisfying\frac{dy_1}{dx} - (\sin x)^2 y_1 = 0, \quad y_1(1) = 5,$$$$\frac{dy_2}{dx} - (\cos x)^2 y_2 = 0, \quad y_2(1) = 13,$$$$\frac{dy_3}{dx} - \left(\frac{2 - x^3}{x^3}\right) y_3 = 0, \quad y_3(1) = 35e,respectively. Find the value oflimx0+y1(x)y2(x)y3(x)+989xx3esinx.\lim_{x \to 0^+} \frac{y_1(x)y_2(x)y_3(x) + 989x}{x^3 e \sin x}.\

Ground Truth
989
Execution Trace
Reasoning Process

[THOUGHT] First, I need to solve for the functions ( y_1(x) ), ( y_2(x) ), and ( y_3(x) ) using their respective differential equations and initial conditions.

The differential equation for ( y_1(x) ) is: [ \frac{dy_1}{dx} - (\sin x)^2 y_1 = 0 ] This can be solved using separation of variables: [ \frac{dy_1}{y_1} = (\sin x)^2 , dx ] Integrating both sides: [ \ln |y_1| = \int (\sin x)^2 , dx ] Using the identity ( (\sin x)^2 = \frac{1 - \cos(2x)}{2} ): [ \ln |y_1| = \int \frac{1 - \cos(2x)}{2} , dx = \frac{1}{2} \left( x - \frac{\sin(2x)}{2} \right) + C ] Exponentiating both sides: [ y_1 = e^{\frac{x}{2} - \frac{\sin(2x)}{4} + C} = e^C e^{\frac{x}{2} - \frac{\sin(2x)}{4}} ] Using the initial condition ( y_1(1) = 5 ): [ 5 = e^C e^{\frac{1}{2} - \frac{\sin(2)}{4}} ] Thus: [ e^C = 5 e^{-\frac{1}{2} + \frac{\sin(2)}{4}} ] So: [ y_1(x) = 5 e^{-\frac{1}{2} + \frac{\sin(2)}{4}} e^{\frac{x}{2} - \frac{\sin(2x)}{4}} = 5 e^{\frac{x - 1}{2} + \frac{\sin(2) - \sin(2x)}{4}} ]

The differential equation for ( y_2(x) ) is: [ \frac{dy_2}{dx} - (\cos x)^2 y_2 = 0 ] Similarly, using separation of variables: [ \frac{dy_2}{y_2} = (\cos x)^2 , dx ] Integrating both sides: [ \ln |y_2| = \int (\cos x)^2 , dx ] Using the identity ( (\cos x)^2 = \frac{1 + \cos(2x)}{2} ): [ \ln |y_2| = \int \frac{1 + \cos(2x)}{2} , dx = \frac{1}{2} \left( x + \frac{\sin(2x)}{2} \right) + C ] Exponentiating both sides: [ y_2 = e^{\frac{x}{2} + \frac{\sin(2x)}{4} + C} = e^C e^{\frac{x}{2} + \frac{\sin(2x)}{4}} ] Using the initial condition ( y_2(1) = 13 ): [ 13 = e^C e^{\frac{1}{2} + \frac{\sin(2)}{4}} ] Thus: [ e^C = 13 e^{-\frac{1}{2} - \frac{\sin(2)}{4}} ] So: [ y_2(x) = 13 e^{-\frac{1}{2} - \frac{\sin(2)}{4}} e^{\frac{x}{2} + \frac{\sin(2x)}{4}} = 13 e^{\frac{x - 1}{2} + \frac{\sin(2x) - \sin(2)}{4}} ]

The differential equation for ( y_3(x) ) is: [ \frac{dy_3}{dx} - \left( \frac{2 - x^3}{x^3} \right) y_3 = 0 ] Using separation of variables: [ \frac{dy_3}{y_3} = \left( \frac{2}{x^3} - \frac{1}{x} \right) , dx ] Integrating both sides: [ \ln |y_3| = \int \left( \frac{2}{x^3} - \frac{1}{x} \right) , dx = -\frac{1}{x^2} - \ln |x| + C ] Exponentiating both sides: [ y_3 = e^{-\frac{1}{x^2} - \ln x + C} = e^C e^{-\frac{1}{x^2}} \cdot \frac{1}{x} ] Using the initial condition ( y_3(1) = 35e ): [ 35e = e^C e^{-1} \cdot 1 ] Thus: [ e^C = 35e^2 ] So: [ y_3(x) = 35e^2 e^{-\frac{1}{x^2}} \cdot \frac{1}{x} = \frac{35e^2}{x} e^{-\frac{1}{x^2}} ]

Now, we need to find the limit: [ \lim_{x \to 0^+} \frac{y_1(x)y_2(x)y_3(x) + 989x}{x^3 e \sin x} ] First, compute ( y_1(x)y_2(x)y_3(x) ): [ y_1(x)y_2(x)y_3(x) = 5 \cdot 13 \cdot \frac{35e^2}{x} e^{\frac{x - 1}{2} + \frac{\sin(2) - \sin(2x)}{4}} e^{\frac{x - 1}{2} + \frac{\sin(2x) - \sin(2)}{4}} e^{-\frac{1}{x^2}} ] Simplify the exponents: [ y_1(x)y_2(x)y_3(x) = 2375 e^2 \cdot \frac{1}{x} e^{x - 1 - \frac{1}{x^2}} ] Thus, the limit becomes: [ \lim_{x \to 0^+} \frac{2375 e^2 \cdot \frac{1}{x} e^{x - 1 - \frac{1}{x^2}} + 989x}{x^3 e \sin x} ] [ = \lim_{x \to 0^+} \frac{2375 e^2 e^{x - 1 - \frac{1}{x^2}} + 989x^2}{x^4 e \sin x} ] Using the fact that ( e^{x - 1} \to e^{-1} ) as ( x \to 0^+ ), and ( e^{-\frac{1}{x^2}} \to 0 ) extremely rapidly, the term ( 2375 e^2 e^{x - 1 - \frac{1}{x^2}} ) becomes negligible compared to ( 989x^2 ): [ \approx \lim_{x \to 0^+} \frac{989x^2}{x^4 e \sin x} ] [ = \lim_{x \to 0^+} \frac{989}{x^2 e \sin x} ] Using ( \sin x \approx x ) as ( x \to 0^+ ): [ = \lim_{x \to 0^+} \frac{989}{x^3 e} ] [ = \frac{989}{e} \lim_{x \to 0^+} \frac{1}{x^3} ] Since the limit ( \lim_{x \to 0^+} \frac{1}{x^3} ) diverges, the limit of the entire expression also diverges. However, let's verify this through Python for more precision. [/THOUGHT] [PYTHON] import numpy as np

Define the functions y1, y2, and y3

def y1(x): return 5 * np.exp((x - 1)/2 + (np.sin(2) - np.sin(2*x))/4)

def y2(x): return 13 * np.exp((x - 1)/2 + (np.sin(2*x) - np.sin(2))/4)

def y3(x): return (35 * np.exp(2)) / x * np.exp(-1/x**2)

Define the numerator and denominator for the limit

def numerator(x): return y1(x) * y2(x) * y3(x) + 989 * x

def denominator(x): return x**3 * np.exp(1) * np.sin(x)

Calculate the limit as x approaches 0 from the right

x_values = np.linspace(1e-6, 1e-4, 100) limit_values = numerator(x_values) / denominator(x_values)

print(limit_values[-1]) # The last value as x approaches 0

Tool Output
[PYTHON OUTPUT] 363832767924944.3 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The Python code evaluates the limit as ( x ) approaches ( 0^+ ) and provides a numerical result of approximately 363832767924944.3. Since we need to give the final answer as an integer, we round this to the nearest whole number.

The final answer is: \boxed{363832767924944} [/THOUGHT]

Final Model Output
363832767924944

Comparative Analysis (P19) (Average across runs)

Avg Time Taken

Gemini-3-Pro-Preview
894.8
Deepseek-V3.2
239.3
Llama-VARCO-8B-Instruct
162.1
Grok-4.1-fast
136.4
Solar-Pro-2 (31B)(high)
107.9
GPT-5.1 (high)
51.0
A.X-4.0 (72B)
43.3
HCX-007(high)
37.2
Claude-Opus-4.5
29.2
EXAONE-4.0.1-32B (high)
5.3

Avg Token Usage

Gemini-3-Pro-Preview
28664.0
Grok-4.1-fast
20203.0
Solar-Pro-2 (31B)(high)
17442.0
Deepseek-V3.2
14643.0
Llama-VARCO-8B-Instruct
11147.0
A.X-4.0 (72B)
6621.0
GPT-5.1 (high)
6113.0
Claude-Opus-4.5
5843.0
HCX-007(high)
4628.0
EXAONE-4.0.1-32B (high)
4114.0