diff --git a/题库0.3/Problems.json b/题库0.3/Problems.json index f03f8fb6..47be6070 100644 --- a/题库0.3/Problems.json +++ b/题库0.3/Problems.json @@ -638795,6 +638795,66 @@ "space": "", "unrelated": [] }, + "023632": { + "id": "023632", + "content": "证明: 设 $\\overrightarrow{a}$ 与 $\\overrightarrow{b}$、$\\overrightarrow{c}$ 是向量, $\\lambda$ 是实数, 则\\\\\n(1) 向量数量积的交换律: $\\overrightarrow{a}\\cdot \\overrightarrow{b}=\\overrightarrow{b}\\cdot \\overrightarrow{a}$;\\\\\n(2) 向量数量积对数乘的结合律: $(\\lambda \\overrightarrow{a}) \\cdot \\overrightarrow{b}=\\overrightarrow{a}\\cdot(\\lambda \\overrightarrow{b})$;\\\\\n(3) 向量数量积对加法的分配律: $\\overrightarrow{a}\\cdot(\\overrightarrow{b}+\\overrightarrow{c})=\\overrightarrow{a}\\cdot \\overrightarrow{b}+\\overrightarrow{a}\\cdot \\overrightarrow{c}$.", + "objs": [], + "tags": [], + "genre": "解答题", + "ans": "", + "solution": "", + "duration": -1, + "usages": [], + "origin": "自拟题目", + "edit": [ + "20240122\t赵琍琍" + ], + "same": [], + "related": [], + "remark": "", + "space": "4em", + "unrelated": [] + }, + "023633": { + "id": "023633", + "content": "如图, 给定边长为 $6$ 的正三角形 $ABC$. 求 $\\overrightarrow{AB}\\cdot \\overrightarrow{AC}$ 和 $\\overrightarrow{AB}\\cdot \\overrightarrow{BC}$.\n\\begin{center}\n\\begin{tikzpicture}[>=latex]\n\\draw (0,0) node [below left] {$B$} coordinate (B);\n\\draw (2,0) node [below right] {$C$} coordinate (C);\n\\draw (60:2) node [above] {$A$} coordinate (A);\n\\draw [->] (A)--(B);\n\\draw [->] (A)--(C);\n\\draw [->] (B)--(C);\n\\end{tikzpicture}\n\\end{center}", + "objs": [], + "tags": [], + "genre": "解答题", + "ans": "", + "solution": "", + "duration": -1, + "usages": [], + "origin": "自拟题目", + "edit": [ + "20240122\t赵琍琍" + ], + "same": [], + "related": [], + "remark": "", + "space": "4em", + "unrelated": [] + }, + "023634": { + "id": "023634", + "content": "已知向量 $\\overrightarrow{a}, \\overrightarrow{b}, \\overrightarrow{c}$ 满足 $\\overrightarrow{a}+\\overrightarrow{b}+\\overrightarrow{c}=\\overrightarrow{0}$, $(\\overrightarrow{a}-\\overrightarrow{b}) \\cdot(\\overrightarrow{a}-\\overrightarrow{c})=0$, $|\\overrightarrow{b}-\\overrightarrow{c}|=9$, 求 $|\\overrightarrow{a}|$.", + "objs": [], + "tags": [], + "genre": "解答题", + "ans": "", + "solution": "", + "duration": -1, + "usages": [], + "origin": "自拟题目", + "edit": [ + "20240122\t赵琍琍" + ], + "same": [], + "related": [], + "remark": "", + "space": "4em", + "unrelated": [] + }, "030001": { "id": "030001", "content": "若$x,y,z$都是实数, 则:(填写``\\textcircled{1} 充分非必要、\\textcircled{2} 必要非充分、\\textcircled{3} 充要、\\textcircled{4} 既非充分又非必要''之一)\\\\\n(1) ``$xy=0$''是``$x=0$''的\\blank{50}条件;\\\\\n(2) ``$x\\cdot y=y\\cdot z$''是``$x=z$''的\\blank{50}条件;\\\\\n(3) ``$\\dfrac xy=\\dfrac yz$''是``$xz=y^2$''的\\blank{50}条件;\\\\\n(4) ``$|x |>| y|$''是``$x>y>0$''的\\blank{50}条件;\\\\\n(5) ``$x^2>4$''是``$x>2$'' 的\\blank{50}条件;\\\\\n(6) ``$x=-3$''是``$x^2+x-6=0$'' 的\\blank{50}条件;\\\\\n(7) ``$|x+y|<2$''是``$|x|<1$且$|y|<1$'' 的\\blank{50}条件;\\\\\n(8) ``$|x|<3$''是``$x^2<9$'' 的\\blank{50}条件;\\\\\n(9) ``$x^2+y^2>0$''是``$x\\ne 0$'' 的\\blank{50}条件;\\\\\n(10) ``$\\dfrac{x^2+x+1}{3x+2}<0$''是``$3x+2<0$'' 的\\blank{50}条件;\\\\\n(11) ``$0