F(X)是偶函数,定义域R,F(X-1）是奇函数,若F(1)=9,F（9）=?

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据题得f(x) = (-x)
f(x - 1) = f(-x-1)
所以f(-x-1) = f(x+1)
f(x - 1) = f(x + 1)
将x替换为x + 1,得
f(x) = f(x + 2)
此函数为周期函数,周期T = 2
f(9) = f(2 * 4 + 1) = f(1) = 9