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题目 #19428

UUID
78efd430-27d5-4c00-8167-06ff05445273
来源
A中考/2026江苏中考期末数学试卷+答案615.pdf 第 2 页,bbox [45.0, 286.69, 399.07, 308.3]
题型 / 学科
fill_blank / math / SENIOR
知识树
KT_SENIOR_MATH_STANDARD
难度
难度 2 / 5 简单 · 单一知识点
QA 状态
存疑 / 待修复 重试 0 次,得分 -
最终题 ID
-
错误
处理异常: LLM call failed after retries: HTTPConnectionPool(host='127.0.0.1', port=8091): Read timed out. (read timeout=120) [endpoints: http://127.0.0.1:8092/v1 -> http://127.0.0.1:8091/v1]

最终题干渲染(f_body 预览)

在等腰\(\triangle ABC\)中,\(AB = AC = 3\),\(\cos B = \frac{1}{3}\),那么\(\cos \angle A =\)______.

答案 / 解析

答案(f_answer)

9

解析(f_ways)

过点 A 作 AD ⊥BC,垂足为 D,过点 C 作 CE ⊥AB,垂足为 E,在Rt △ADB 中,cos∠B = BD\(1 _{AB}\)= _{3}, ∴BD = 1\(1 _{3}\)AB = 1. ∵AB = AC, AD ⊥BC,所以BD = DC, ∴BC = 2, AD =\(\sqrt{AB^{2}}\)−\(BD^{2}\)=\(\sqrt{3^{2}}\)−\(1^{2}\)= 2√2,因为_{2}AB ⋅ 7 AE\(\frac{7}{3}\)CE = _{2}BC ⋅AD, ∴CE = AB = 3 = _{3},所以AE =\(\sqrt{AC^{2}}\)−\(CE^{2}\)= _{3},∴cos∠BAC = _{AC}= _{3}= _{9}.^{7} 1 BC⋅AD\(2\times 2√2 4√2 2\)

原图与资产(1)

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打开
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审计记录

阶段审计器结果得分依据(简短)
STRUCTURE structure-rule PASS 0.900
FORMULA formula-auditor PASS 1.000
KNOWLEDGE knowledge-auditor WARN -
VISION vision-auditor PASS 0.900
SOLVER blind-solver PASS 0.950
CRITIC critic PASS 0.950
SYMBOLIC symbolic-auditor PASS 0.900

知识点(0)

无

事件

时间阶段级别消息
2026-09-24 09:58:04ERRORERROR处理异常: LLM call failed after retries: HTTPConnectionPool(host='127.0.0.1', port=8091): Read timed out. (read timeout=120) [endpoints: http://127.0.0.1:8092/v1 -> http://127.0.0.1:8091/v1]
2026-09-24 09:52:53FORMULAWARN公式转换未确认,保留原文本: solution