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                                    "content": "12. 秩(A)=秩([A|b])=n（方阵满秩）意味着？\nA. 无解\nB. 唯一解"
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                                    "content": " \nB.  "
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                                    "type": "inline_equation",
                                    "content": "O(n^{2})"
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                                    "type": "text",
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                                    "type": "inline_equation",
                                    "content": "O(n^{3})"
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                                    "type": "text",
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                                    "type": "inline_equation",
                                    "content": "O(2^{n})"
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                                    "content": "15. 只要 x，应优先用哪个 numpy 接口？\nA. np.linalg.inv(A) @ b\nB. np.linalg.solve(A, b)\nC. 手写三重循环求伴随\nD. 随机猜"
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                                    "content": "16. 昨天牛顿步 H d = -梯度，对应今晚的？\nA. 求特征值\nB. 解一个线性方程组\nC. 画等高线\nD. 泰勒余项"
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                                    "type": "text",
                                    "content": "17. 病态方程组的几何图像是?\nA. 两直线垂直\nB. 两直线夹角很小\nC. 两直线重合于坐标轴\nD. 没有直线"
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                                    "content": "18. cond(A) 很大表示?\nA. 一定无解\nB. A 对扰动敏感（病态）"
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                                    "content": "13. 秩(A)<秩([A|b]) 意味着?\nA. 唯一解\nB. 无解\nC. 必有无穷解\nD. A 可逆"
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                                    "content": " \nB.  "
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                                    "type": "inline_equation",
                                    "content": "O(n^{3})"
                                },
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                                    "type": "text",
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                                    "type": "inline_equation",
                                    "content": "O(2^{n})"
                                }
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                                    "type": "text",
                                    "content": "15. 只要 x，应优先用哪个 numpy 接口？\nA. np.linalg.inv(A) @ b\nB. np.linalg.solve(A, b)\nC. 手写三重循环求伴随\nD. 随机猜"
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                                    "type": "text",
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                                    "type": "text",
                                    "content": "17. 病态方程组的几何图像是?\nA. 两直线垂直\nB. 两直线夹角很小\nC. 两直线重合于坐标轴\nD. 没有直线"
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                                    "content": "18. cond(A) 很大表示?\nA. 一定无解\nB. A 对扰动敏感（病态）"
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                                    "content": "C. 一定有无穷解\nD. 运算量为 0"
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                                    "content": "19. LU 分解在消元里的角色，最接近？\nA. 把消元乘数存成 L，三角形存成 U，换 b 时只回代\nB. 求特征值\nC. 随机采样\nD. 画图"
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                                    "content": "21. 超定方程组（方程比未知数多）通常怎么处理？\nA. 必无解所以放弃\nB. 最小二乘，解（A转置） "
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                                    "content": "A \\times = (A \\text{转置})b"
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                                    "type": "text",
                                    "content": " \nC. 随机删方程到正方形\nD. 改用  "
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                                {
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                                    "type": "inline_equation",
                                    "content": "\\sin"
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                                    "type": "text",
                                    "content": "22. 《九章算术》「方程」章与高斯消元的关系？\nA. 毫无关系\nB. 已有用行相减解线性方程组的术\nC. 发明了 Adam\nD. 只讲圆"
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                                    "content": "23. "
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                                    "type": "inline_equation",
                                    "content": "3 \\times 3"
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                                    "bbox": [
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                                    "type": "text",
                                    "content": " 消元后最后一行变成000|5，结论是？A. 唯一解B. 无解C. 无穷解D. "
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                                    "content": "x = 5"
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                                    "type": "text",
                                    "content": "24. "
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                                    "type": "inline_equation",
                                    "content": "3 \\times 3"
                                },
                                {
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                                    "type": "text",
                                    "content": " 消元后最后一行变成 "
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                                    "type": "inline_equation",
                                    "content": "000 \\mid 0"
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                                    "type": "text",
                                    "content": "，且前两行独立，结论是？A. 无解B. 无穷多解（少一条真正约束）"
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                                    "content": "A \\times = (A \\text{转置})b"
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                                    "content": " \nC. 随机删方程到正方形\nD. 改用  "
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                                    "content": "\\sin"
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                                    "content": "22. 《九章算术》「方程」章与高斯消元的关系？\nA. 毫无关系\nB. 已有用行相减解线性方程组的术\nC. 发明了 Adam\nD. 只讲圆"
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                                    "content": "3 \\times 3"
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                                    "content": " 消元后最后一行变成000|5，结论是？A. 唯一解B. 无解C. 无穷解D. "
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                                    "content": "x = 5"
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                                    "content": "24. "
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                                    "type": "inline_equation",
                                    "content": "3 \\times 3"
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                                    "type": "text",
                                    "content": " 消元后最后一行变成 "
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                                    "content": "000 \\mid 0"
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                                    "content": "，且前两行独立，结论是？A. 无解B. 无穷多解（少一条真正约束）"
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                                    "content": "C. 唯一解  \nD. 一定病态"
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                                    "content": "29. np.linalg.solve 在 A 奇异时通常?\nA. 静默返回 0\nB. 报错（LinAlgError）\nC. 返回无穷解的一个代表\nD. 自动改用 Adam"
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                                    "content": "30. 今晚最该带走的一句？\nA. 所有方程组都有唯一解\nB. 先会消元解 Ax=b；能 solve 就不要 inv；牛顿步也是解方程"
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