Problem Analysis #20

GPT-5.2 (high) · Run 1

22.25s
5,568 toks
Problem Statement

Let a function f(x)f(x) defined on the set of all real numbers satisfy

f(x)=xsin(πx)for x[0,2],f(x) = x \sin(\pi x) \qquad \text{for } x \in [0,2],

and

f(x)=2f(x2)for all real x.f(x) = 2 f(x-2) \qquad \text{for all real } x.

Consider the region enclosed by the curve y=f(x)y = f(x), the line

y=21012(x2026),y = 2^{1012}(x - 2026),

and the two vertical lines x=2026x = 2026 and x=2027x = 2027.The area of this region is equal to

21012(p+qπ+r3π),2^{1012}\left(p + \frac{q}{\pi} + \frac{r\sqrt{3}}{\pi}\right),

for some rational numbers p,q,rp, q, r.Find the value of 2028pqr2028 \cdot p \cdot q \cdot r.oindent

Ground Truth
1352
Execution Trace
Reasoning Process

[THOUGHT] Map x in [2026,2027] to t=x-2026 in [0,1]. Use the recurrence f(x)=2 f(x-2) to express f(2026+t)=2^{1013} f(t)=2^{1013} t sin(πt). The line is y=2^{1012}t. The vertical scale factor 2^{1012} will factor out, leaving an integral of t*|2 sin(πt)−1| over t∈[0,1]. Determine sign changes where sin(πt)=1/2, i.e., t=1/6 and 5/6, and integrate piecewise. Then match the result to p+q/π+r√3/π and compute 2028·p·q·r. [/THOUGHT] [PYTHON] import sympy as sp

t = sp.symbols('t', real=True) expr = t*(2sp.sin(sp.pit) - 1)

I = sp.integrate(t*(1-2sp.sin(sp.pit)), (t, 0, sp.Rational(1,6))) \

  • sp.integrate(t*(2sp.sin(sp.pit)-1), (t, sp.Rational(1,6), sp.Rational(5,6))) \
  • sp.integrate(t*(1-2sp.sin(sp.pit)), (t, sp.Rational(5,6), 1))

I_simplified = sp.simplify(I) print("I =", I_simplified)

Express I as p + q/pi + r*sqrt(3)/pi

p, q, r = sp.symbols('p q r') target = p + q/sp.pi + r*sp.sqrt(3)/sp.pi

Solve for p,q,r by matching coefficients in basis {1, 1/pi, sqrt(3)/pi}

Rewrite I in that basis

I_rewritten = sp.nsimplify(I_simplified, [sp.pi, sp.sqrt(3)], rational=True) print("I nsimplify =", I_rewritten)

Extract p,q,r by solving linear system after multiplying by pi

Let I = p + (q + rsqrt3)/pi. So piI = ppi + q + rsqrt3.

eq = sp.Eq(sp.piI_simplified, psp.pi + q + r*sp.sqrt(3)) sol = sp.solve(eq, [p, q, r], dict=True) print("sol =", sol)

Since single equation for three unknowns, use coefficient comparison:

Represent pi*I in basis {pi, 1, sqrt3}

expr_piI = sp.simplify(sp.piI_simplified) print("piI =", expr_piI)

Collect in terms of pi and sqrt(3)

expr_collected = sp.collect(expr_piI, [sp.pi, sp.sqrt(3)], evaluate=False) print("collected dict:", expr_collected)

Determine coefficients:

expr_piI should be Api + B + Csqrt3

A = sp.simplify(sp.expand(expr_piI).coeff(sp.pi, 1)) # coefficient of pi rest = sp.simplify(expr_piI - Asp.pi) C = sp.simplify(rest.coeff(sp.sqrt(3), 1)) B = sp.simplify(rest - Csp.sqrt(3)) print("A,B,C =", A,B,C)

p_val = A q_val = B r_val = C

print("p,q,r =", p_val, q_val, r_val)

value = sp.simplify(2028 * p_val * q_val * r_val) print("2028pqr =", value) print("as integer?", sp.nsimplify(value)) [/PYTHON][THOUGHT] Map x in [2026,2027] to t=x-2026 in [0,1]. Use the recurrence f(x)=2 f(x-2) to express f(2026+t)=2^{1013} f(t)=2^{1013} t sin(πt). The line is y=2^{1012}t. The vertical scale factor 2^{1012} will factor out, leaving an integral of t|2 sin(πt)−1| over t∈[0,1]. Determine sign changes where sin(πt)=1/2, i.e., t=1/6 and 5/6, and integrate piecewise. Then match the result to p+q/π+r√3/π and compute 2028·p·q·r. [/THOUGHT] [PYTHON] import sympy as sp

t = sp.symbols('t', real=True) expr = t*(2sp.sin(sp.pit) - 1)

I = sp.integrate(t*(1-2sp.sin(sp.pit)), (t, 0, sp.Rational(1,6))) \

  • sp.integrate(t*(2sp.sin(sp.pit)-1), (t, sp.Rational(1,6), sp.Rational(5,6))) \
  • sp.integrate(t*(1-2sp.sin(sp.pit)), (t, sp.Rational(5,6), 1))

I_simplified = sp.simplify(I) print("I =", I_simplified)

Work with piI = ppi + q + r*sqrt(3)

expr_piI = sp.simplify(sp.piI_simplified) print("piI =", expr_piI)

A = sp.simplify(sp.expand(expr_piI).coeff(sp.pi, 1)) # coefficient of pi rest = sp.simplify(expr_piI - Asp.pi) C = sp.simplify(rest.coeff(sp.sqrt(3), 1)) B = sp.simplify(rest - Csp.sqrt(3))

p_val, q_val, r_val = A, B, C print("p,q,r =", p_val, q_val, r_val)

value = sp.simplify(2028 * p_val * q_val * r_val) print("2028pq*r =", value) print("integer check:", sp.Integer(value)) [/PYTHON]

Tool Output
[PYTHON OUTPUT] I = (-12 - pi + 12*sqrt(3))/(6*pi) I nsimplify = (-12 - pi + 12*sqrt(3))/(6*pi) sol = [{p: (-q - sqrt(3)*r - 2 - pi/6 + 2*sqrt(3))/pi}] pi*I = -2 - pi/6 + 2*sqrt(3) collected dict: {sqrt(3): 2, pi: -1/6, 1: -2} A,B,C = -1/6 -2 2 p,q,r = -1/6 -2 2 2028*p*q*r = 1352 as integer? 1352 [/PYTHON OUTPUT] [PYTHON OUTPUT] I = (-12 - pi + 12*sqrt(3))/(6*pi) pi*I = -2 - pi/6 + 2*sqrt(3) p,q,r = -1/6 -2 2 2028*p*q*r = 1352 integer check: 1352 [/PYTHON OUTPUT]
Reasoning Process

[THOUGHT] From the computed integral, p=16p=-\frac16, q=2q=-2, r=2r=2. Thus 2028pqr=13522028\cdot p\cdot q\cdot r=1352.

1352\boxed{1352}
Final Model Output
1352

Comparative Analysis (P20) (Average across runs)

Avg Time Taken

K-EXAONE-236B-A23B
1117.7
Solar-Open-100B
743.0
Solar-Pro-2 (31B)(high)
209.1
Llama-VARCO-8B-Instruct
194.6
Gemini-3-Pro-Preview
117.1
A.X-4.0 (72B)
98.1
Grok-4.1-fast
91.6
Kanana-2-30B-Thinking
82.5
HCX-007(high)
65.9
K-EXAONE-236B-A23B
64.2
GPT-5.1 (high)
59.3
Deepseek-V3.2
40.9
Kanana-2-30B-Thinking-2601
39.3
Claude-Opus-4.5
27.1
GPT-5.2 (high)
22.2
EXAONE-4.0.1-32B (high)
7.6

Avg Token Usage

K-EXAONE-236B-A23B
231,341
Solar-Open-100B
23,307
Kanana-2-30B-Thinking
15,652
Grok-4.1-fast
15,328
Gemini-3-Pro-Preview
13,814
Solar-Pro-2 (31B)(high)
12,507
Kanana-2-30B-Thinking-2601
9,180
HCX-007(high)
7,833
GPT-5.1 (high)
7,486
Deepseek-V3.2
7,264
Llama-VARCO-8B-Instruct
7,065
K-EXAONE-236B-A23B
6,115
GPT-5.2 (high)
5,568
Claude-Opus-4.5
5,400
EXAONE-4.0.1-32B (high)
5,036
A.X-4.0 (72B)
3,005