Problem Analysis #8

41.81s
9,159 toks
Problem Statement

Answer the following questions. Here, for any complex value zz, zˉ\bar{z} is the complex conjugate of zz, argz\arg z is the argument of zz, z|z| is the absolute value of zz, and ii is the imaginary unit.\subsection*{I.}Sketch the region of zz on the complex plane that satisfieszzˉ+2(z+zˉ)+3i(zzˉ)+20.z\bar{z} + \sqrt{2}(z + \bar{z}) + 3i(z - \bar{z}) + 2 \leq 0.\subsection*{II.}Consider the complex-valued functionf(z)=z22(z2+2i)z2.f(z) = \frac{z^2 - 2}{(z^2 + 2i)z^2}.

  • [(1)] Find all the poles of f(z)f(z) as well as the orders and residues at the poles.

  • [(2)] By applying the residue theorem, find the value of the integral I1=Cf(z)dz, I_1 = \oint_C f(z)\,dz, where the integration path CC is the circle in the counterclockwise direction given by z+1=2|z + 1| = 2. \subsection*{III.}

  • [(1)] Let g(z)g(z) be a complex-valued function satisfying limzg(z)=0 \lim_{|z|\to\infty} g(z) = 0 for 0 $$\leq$$ \arg z $$\leq$$ $$\pi$$$. Let C_Rbethesemicircle,withradiusbe the semicircle, with radiusR, in the upper half of the complex plane with center at the origin. Show that $$ \lim_{R\to\infty} \int_{C_R} e^{iaz} g(z)\,dz = 0, $$ where a$ is a positive real number.

  • [(2)] Find the value of the integral I2=0sinxxdx. I_2 = \int_0^{\infty} \frac{\sin x}{x}\,dx. \subsection*{IV. Final quantity}In I, the region for zz is a disk. Let RR be its radius and cc be its center. In II(2), let RinR_{\mathrm{in}} be the sum of the residues of f(z)f(z) over all poles lying inside the circle z+1=2|z + 1| = 2. In II(2) and III(2), let I1I_1 and I2I_2 be the values of the corresponding integrals.DefineS:=(R2+c2)2(I1I2)31Rin,K:=999S2+7.S := (R^2 + |c|^2)^2 \left(\frac{|I_1|}{I_2}\right)^3 \cdot \frac{1}{|R_{\mathrm{in}}|},\qquad\mathcal{K} := 999\,S^2 + 7.Compute the integer K\mathcal{K}.\

Ground Truth
40919040007
Execution Trace
Reasoning Process

[THOUGHT] To solve the problem, we break it down into parts as follows:

I. Region of z: The inequality ( z\bar{z} + \sqrt{2}(z + \bar{z}) + 3i(z - \bar{z}) + 2 \leq 0 ) is transformed into a circle equation by substituting ( z = x + iy ). This results in the circle ( (x + \sqrt{2})^2 + (y - 3)^2 \leq 9 ), giving a radius ( R = 3 ) and center ( c = -\sqrt{2} + 3i ). The modulus of the center is ( |c| = \sqrt{11} ).

II(1). Poles and Residues of ( f(z) ): The function ( f(z) = \frac{z^2 - 2}{(z^2 + 2i)z^2} ) has poles at ( z = 0 ) (order 2), ( z = 1 - i ), and ( z = -1 + i ) (both order 1). The residues are:

  • ( \text{Res}(f, 0) = 0 )
  • ( \text{Res}(f, 1 - i) = \frac{1}{2} )
  • ( \text{Res}(f, -1 + i) = -\frac{1}{2} )

II(2). Integral ( I_1 ): The contour ( |z + 1| = 2 ) includes poles at ( z = 0 ) and ( z = -1 + i ). The sum of residues inside is ( 0 + (-\frac{1}{2}) = -\frac{1}{2} ). Thus, ( I_1 = 2\pi i \times (-\frac{1}{2}) = -\pi i ), giving ( |I_1| = \pi ).

III(2). Integral ( I_2 ): The integral ( \int_0^\infty \frac{\sin x}{x} , dx ) is known to be ( \frac{\pi}{2} ).

Final Calculation: Using the values:

  • ( R = 3 ), ( |c| = \sqrt{11} )
  • ( |I_1| = \pi ), ( I_2 = \frac{\pi}{2} )
  • ( |R_{\text{in}}| = \frac{1}{2} )

We compute: [ S = (R^2 + |c|^2)^2 \left( \frac{|I_1|}{I_2} \right)^3 \cdot \frac{1}{|R_{\text{in}}|} = (9 + 11)^2 \cdot 2^3 \cdot 2 = 400 \cdot 8 \cdot 2 = 6400 ] [ \mathcal{K} = 999 \cdot S^2 + 7 = 999 \cdot 40960000 + 7 = 40919040007 ]

[PYTHON]

Calculations for the final answer

R = 3 c_modulus = (20.5)2 + 32 R_squared = R2 c_squared = c_modulus sum_R_c = R_squared + c_squared S_squared = sum_R_c2 I1_abs = 3.141592653589793 # pi I2 = 3.141592653589793 / 2 # pi/2 ratio = I1_abs / I2 ratio_cubed = ratio3 R_in_abs = 0.5 S = S_squared * ratio_cubed * (1 / R_in_abs) K = 999 * S**2 + 7 print(int(K)) [/PYTHON]

Tool Output
[PYTHON OUTPUT] 40919040007 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] The Python output confirms the calculation of (\mathcal{K} = 40919040007). [/THOUGHT] \boxed{40919040007}

Final Model Output
40919040007

Comparative Analysis (P8) (Average across runs)

Avg Time Taken

Gemini-3-Pro-Preview
276.8
Deepseek-V3.2
202.1
GPT-5.1 (high)
91.6
Llama-VARCO-8B-Instruct
63.3
Grok-4.1-fast
60.2
A.X-4.0 (72B)
58.6
Claude-Opus-4.5
42.7
Solar-Pro-2 (31B)(high)
41.8
HCX-007(high)
20.4
EXAONE-4.0.1-32B (high)
5.5

Avg Token Usage

Gemini-3-Pro-Preview
15034.0
Claude-Opus-4.5
12309.0
Grok-4.1-fast
10596.0
Solar-Pro-2 (31B)(high)
9159.0
A.X-4.0 (72B)
9042.0
GPT-5.1 (high)
8139.0
Deepseek-V3.2
8047.0
HCX-007(high)
5016.0
EXAONE-4.0.1-32B (high)
4747.0
Llama-VARCO-8B-Instruct
1832.0