当 x < 0 时,
-x > 0
f(-x) = 1 + 2^(-x)
因为 f(x)是奇函数
所以f(x) = -f(-x) = -1 - 2^(-x) 且 f(0) = 0
所以
f(x) = 1 + 2^x x > 0
= 0 x = 0
= -1 - 2^(-x) x < 0
当 x < 0 时,
-x > 0
f(-x) = 1 + 2^(-x)
因为 f(x)是奇函数
所以f(x) = -f(-x) = -1 - 2^(-x) 且 f(0) = 0
所以
f(x) = 1 + 2^x x > 0
= 0 x = 0
= -1 - 2^(-x) x < 0