求 f(x) + f(1-x) f(x) = 1/(2^x + √2）f(1-x) = 1/[2^(1-x) + √2） .(分子、分母同时乘以 2^x )= 2^x/(2 + √2 * 2^x) .（分母中提取出 √2）= (2^x/√2) * (1/√2 + 2^x) = (2^x/√2) * f(x)f(x) + f(1-x)= (1+ ...