令y = ln[x + √(x² + 1)],确保y是奇函数才存在反函数y⁻¹
e^y = x + √(x² + 1)
√(x² + 1) = e^y - x
x² + 1 = e^(2y) - 2xe^y + x²
2xe^y = e^(2y) - 1
x = [e^(2y) - 1]/(2e^y)
所以反函数y⁻¹为
y = [e^(2x) - 1]/(2e^x)
y = (1/2)[e^(2x) - 1]e^(- x)
令y = ln[x + √(x² + 1)],确保y是奇函数才存在反函数y⁻¹
e^y = x + √(x² + 1)
√(x² + 1) = e^y - x
x² + 1 = e^(2y) - 2xe^y + x²
2xe^y = e^(2y) - 1
x = [e^(2y) - 1]/(2e^y)
所以反函数y⁻¹为
y = [e^(2x) - 1]/(2e^x)
y = (1/2)[e^(2x) - 1]e^(- x)