题目内容
收藏
纠错
If $$f(x) = x^2 +5$$ for all positive integers $$x$$, which of the following must be true for each positive integer $$x$$?
-
A$$f(x)$$ is an odd integer.
-
B$$f(x)$$ is an even integer.
-
C$$f(x+1)$$ * $$f(x)$$is an odd integer.
-
D$$f(x+1)$$ + $$f(x)$$ is an even integer.
-
E$$f(x+1)$$ - $$f(x)$$ is an odd integer.
E显示答案