增加K0111的四道自拟题目19280:19283

题库0.3/Problems.json

@@ -493865,6 +493865,86 @@
         "space": "4em",
         "unrelated": []
     },
+    "019280": {
+        "id": "019280",
+        "content": "若 $-2 \\leq x \\leq 3$, $-1 \\leq y \\leq 4$, 求 $x-2 y$ 的最小值, 并指出取到最小值时 $x, y$ 的取值.",
+        "objs": [],
+        "tags": [],
+        "genre": "解答题",
+        "ans": "",
+        "solution": "",
+        "duration": -1,
+        "usages": [],
+        "origin": "自拟题目",
+        "edit": [
+            "20230726\t赵琍琍"
+        ],
+        "same": [],
+        "related": [],
+        "remark": "",
+        "space": "4em",
+        "unrelated": []
+    },
+    "019281": {
+        "id": "019281",
+        "content": "``$\\begin{cases}2<x+y<4,\\\\0<x y<3\\end{cases}$''是``$\\begin{cases}2<x<3,\\\\0<y<1\\end{cases}$''的\\bracket{20}.\n\\twoch{充分但非必要条件}{必要但非充分条件}{充分必要条件}{既非充分又非必要条件}",
+        "objs": [],
+        "tags": [],
+        "genre": "选择题",
+        "ans": "",
+        "solution": "",
+        "duration": -1,
+        "usages": [],
+        "origin": "自拟题目",
+        "edit": [
+            "20230726\t赵琍琍"
+        ],
+        "same": [],
+        "related": [],
+        "remark": "",
+        "space": "",
+        "unrelated": []
+    },
+    "019282": {
+        "id": "019282",
+        "content": "已知 $0\\le \\alpha\\le \\beta\\le \\pi$.\\\\\n(1) 求 $\\alpha-\\beta$ 的最大值与最小值;\\\\\n(2) 求 $2 \\alpha-\\beta$ 的最大值与最小值.",
+        "objs": [],
+        "tags": [],
+        "genre": "解答题",
+        "ans": "",
+        "solution": "",
+        "duration": -1,
+        "usages": [],
+        "origin": "自拟题目",
+        "edit": [
+            "20230726\t赵琍琍"
+        ],
+        "same": [],
+        "related": [],
+        "remark": "",
+        "space": "4em",
+        "unrelated": []
+    },
+    "019283": {
+        "id": "019283",
+        "content": "已知 $a<0$, $b>0$, $a+b>0$, 比较 $b,-a, b-a, a-b$ 四个数的大小.",
+        "objs": [],
+        "tags": [],
+        "genre": "解答题",
+        "ans": "",
+        "solution": "",
+        "duration": -1,
+        "usages": [],
+        "origin": "自拟题目",
+        "edit": [
+            "20230726\t赵琍琍"
+        ],
+        "same": [],
+        "related": [],
+        "remark": "",
+        "space": "4em",
+        "unrelated": []
+    },
     "020001": {
         "id": "020001",
         "content": "判断下列各组对象能否组成集合, 若能组成集合, 指出是有限集还是无限集.\\\\\n(1) 上海市控江中学$2022$年入学的全体高一年级新生;\\\\\n(2) 中国现有各省的名称;\\\\\n(3) 太阳、$2$、上海市;\\\\\n(4) 大于$10$且小于$15$的有理数;\\\\\n(5) 末位是$3$的自然数;\\\\\n(6) 影响力比较大的中国数学家;\\\\\n(7) 方程$x^2+x-3=0$的所有实数解;\\\\ \n(8) 函数$y=\\dfrac 1x$图像上所有的点;\\\\ \n(9) 在平面直角坐标系中, 到定点$(0, 0)$的距离等于$1$的所有点;\\\\\n(10) 不等式$3x-10<0$的所有正整数解;\\\\\n(11) 所有的平面四边形.",