Question

f(x)=1-√x+2 求反函数

Answer 1

y=f(x)=1-√(x+2),的定义域为：x≥-2,值域为：y≤1

则

1-y=√(x+2)

(1-y)²=x+2

=>x=(1-y)²-2=y²-2y-1

=>f(x)=1-√x+2 的反函数y=f^(-1)(x)=y²-2y-1 ,(x≤1)