指出下列集合哪些是空集?哪些是有限集?哪些是无限集?急(要写出过程)(1){x|x=2n,n∈N}(2){(x,y)|x-y=2,x∈N,y∈N}
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![指出下列集合哪些是空集?哪些是有限集?哪些是无限集?急(要写出过程)(1){x|x=2n,n∈N}(2){(x,y)|x-y=2,x∈N,y∈N}](/uploads/image/z/10279382-14-2.jpg?t=%E6%8C%87%E5%87%BA%E4%B8%8B%E5%88%97%E9%9B%86%E5%90%88%E5%93%AA%E4%BA%9B%E6%98%AF%E7%A9%BA%E9%9B%86%3F%E5%93%AA%E4%BA%9B%E6%98%AF%E6%9C%89%E9%99%90%E9%9B%86%3F%E5%93%AA%E4%BA%9B%E6%98%AF%E6%97%A0%E9%99%90%E9%9B%86%3F%E6%80%A5%EF%BC%88%E8%A6%81%E5%86%99%E5%87%BA%E8%BF%87%E7%A8%8B%EF%BC%89%EF%BC%881%EF%BC%89%7Bx%7Cx%3D2n%2Cn%E2%88%88N%7D%EF%BC%882%EF%BC%89%7B%28x%2Cy%29%7Cx-y%3D2%2Cx%E2%88%88N%2Cy%E2%88%88N%7D)
指出下列集合哪些是空集?哪些是有限集?哪些是无限集?急(要写出过程)(1){x|x=2n,n∈N}(2){(x,y)|x-y=2,x∈N,y∈N}
指出下列集合哪些是空集?哪些是有限集?哪些是无限集?
急(要写出过程)
(1){x|x=2n,n∈N}
(2){(x,y)|x-y=2,x∈N,y∈N}
指出下列集合哪些是空集?哪些是有限集?哪些是无限集?急(要写出过程)(1){x|x=2n,n∈N}(2){(x,y)|x-y=2,x∈N,y∈N}
因为x=2n,n∈N,表示非负偶数,非负偶数有无穷多个,故{x|x=2n,n∈N}是无限集;
因为满足x-y=2的有序数对有无穷多个,故{(x,y)|x-y=2,x∈N,y∈N}是无限集