{ | |
"source_file": "./raw_volume-zh/volume1/exercise1.tex", | |
"problem_type": "calculation", | |
"problem": "问题9: 已知 $M=\\left\\{x \\mid x=a^2+1, a \\in \\mathbf{N}^*\\right\\}, N=\\left\\{x \\mid x=b^2-4 b+5, b \\in \\mathbf{N}^*\\right\\}$, 则 $M$ 与 $N$ 的关系是", | |
"solution": "解: $M \\varsubsetneqq N$. 由 $a^2+1=(a+2)^2-4 a+5$ 知 $M \\subseteq N$. 但 $1 \\in N, 1 \\notin M$.", | |
"remark": "", | |
"figures": [] | |
} |