diff --git a/题库0.3/Problems.json b/题库0.3/Problems.json index a0ca7532..da1c3b76 100644 --- a/题库0.3/Problems.json +++ b/题库0.3/Problems.json @@ -133888,7 +133888,7 @@ }, "004308": { "id": "004308", - "content": "如图, 经过村庄$A$有两条夹角为$60^\\circ$的公路$AB$、$AC$, 根据规划拟在两条公路之间的区域内建一工厂$P$, 分别在两条公路边上建两个仓库$M$、$N$(异于村庄$A$), 要求$PM=PN=MN=2$(单位: 千米). 记$\\angle MN=\\theta$.\n\\begin{center}\n \\begin{tikzpicture}\n \\draw (0,0) node [below left] {$A$} coordinate (A) -- (3,0) node [below] {$M$} coordinate (M) -- (5,0) node [below] {$B$};\n \\path [name path = lineMN] (M) --++ (135:3);\n \\path [name path = lineAN] (0,0) --++ (60:3);\n \\path [name intersections = {of = lineMN and lineAN, by= N}];\n \\draw (A) -- (N) node [above left] {$N$} --++ (60:2) node [above] {$C$};\n \\draw [dashed] (M) --++ (75:{3/sin(75)*sin(60)}) node [right] {$P$} coordinate (P) -- (N) -- (M) (P) -- (0,0);\n \\draw (2.6,0) arc (180:135:0.4);\n \\path (2.6,0) arc (180:150:0.4) node [left] {$\\theta$};\n \\end{tikzpicture}\n\\end{center}\n(1) 将$AN$、$AM$用含$\\theta$的关系式表示出来;\\\\\n(2) 如何设计(即$AN$、$AM$为多长时), 使得工厂产生的噪声对居民的影响最小(即工厂与村庄的距离$AP$最大)?", + "content": "如图, 经过村庄$A$有两条夹角为$60^\\circ$的公路$AB$、$AC$, 根据规划拟在两条公路之间的区域内建一工厂$P$, 分别在两条公路边上建两个仓库$M$、$N$(异于村庄$A$), 要求$PM=PN=MN=2$(单位: 千米). 记$\\angle AMN=\\theta$.\n\\begin{center}\n \\begin{tikzpicture}\n \\draw (0,0) node [below left] {$A$} coordinate (A) -- (3,0) node [below] {$M$} coordinate (M) -- (5,0) node [below] {$B$};\n \\path [name path = lineMN] (M) --++ (135:3);\n \\path [name path = lineAN] (0,0) --++ (60:3);\n \\path [name intersections = {of = lineMN and lineAN, by= N}];\n \\draw (A) -- (N) node [above left] {$N$} --++ (60:2) node [above] {$C$};\n \\draw [dashed] (M) --++ (75:{3/sin(75)*sin(60)}) node [right] {$P$} coordinate (P) -- (N) -- (M) (P) -- (0,0);\n \\draw (2.6,0) arc (180:135:0.4);\n \\path (2.6,0) arc (180:150:0.4) node [left] {$\\theta$};\n \\end{tikzpicture}\n\\end{center}\n(1) 将$AN$、$AM$用含$\\theta$的关系式表示出来;\\\\\n(2) 如何设计(即$AN$、$AM$为多长时), 使得工厂产生的噪声对居民的影响最小(即工厂与村庄的距离$AP$最大)?", "objs": [], "tags": [ "第三单元" @@ -133900,7 +133900,8 @@ "usages": [], "origin": "2022届高三下学期测验卷12第19题", "edit": [ - "20220705\t王伟叶" + "20220705\t王伟叶", + "20240319\t徐慧" ], "same": [], "related": [], @@ -687173,7 +687174,7 @@ }, "024742": { "id": "024742", - "content": "已知 $\\omega \\in \\mathbf{R}, $``$\\omega=\\pi$''是``函数 $f(x)=\\sin \\omega x \\cdot \\cos \\omega x$ 的最小正周期是 1''的\\blank{50}\n条件;", + "content": "已知 $\\omega \\in \\mathbf{R}, $``$\\omega=\\pi$''是``函数 $f(x)=\\sin \\omega x \\cdot \\cos \\omega x$ 的最小正周期是 1''的\\blank{50}\n条件.", "objs": [], "tags": [], "genre": "填空题", @@ -687183,7 +687184,8 @@ "usages": [], "origin": "自拟题目", "edit": [ - "20240319\t朱敏慧" + "20240319\t朱敏慧", + "20240319\t徐慧" ], "same": [], "related": [