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Algebra Difficulty 3.0 AMC 10/12 Find the answer

Given that f(x)f(x) is an even function on R\mathbb{R}, if the graph of f(x)f(x) is translated one unit to the right, then the resulting graph is that of an odd function. If f(2)=1f(2) = -1, then the value of f(0)+f(1)+f(2)++f(2012)f(0) + f(1) + f(2) + \ldots + f(2012) is

Pick one

Solution

Since f(x)f(x) is an even function on R\mathbb{R}, and f(x1)f(x-1) is an odd function on R\mathbb{R}, we have
f(x)=f(x)f(-x) = f(x), and f(x1)=f(x1)f(-x-1) = -f(x-1), (1)
Therefore, f(x1)=f(x+1)f(-x-1) = f(x+1), (2)
From (1) and (2), we get f(x+1)=f(x1)f(x+1) = -f(x-1) (3) always holds,
Therefore, f(x1)=f(x3)f(x-1) = -f(x-3) (4)
From (3) and (4), we get f(x+1)=f(x3)f(x+1) = f(x-3) always holds,
Therefore, the period of the function is 4.
Since the graph of f(x)f(x) is translated one unit to the right to get an odd function, we have f(01)=0f(0-1) = 0, which means f(1)=0f(-1) = 0. By the property of even functions, we know f(1)=0f(1) = 0, and by periodicity, we know f(3)=0f(3) = 0.
Given f(2)=1f(2) = -1, we have f(2)=1f(-2) = -1, and from f(x+1)=f(x1)f(x+1) = -f(x-1), we know f(0)=1f(0) = 1, thus f(4)=1f(4) = 1.
Therefore, we have f(1)+f(2)+f(3)+f(4)=0f(1) + f(2) + f(3) + f(4) = 0.
Therefore, f(0)+f(1)+f(2)+f(3)++f(2012)=f(0)=1f(0) + f(1) + f(2) + f(3) + \ldots + f(2012) = f(0) = 1.
Hence, the correct answer is B\boxed{\text{B}}.

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Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic and difficulty added by this site.