## lisa123 one year ago consider the following function. f(x)=x^2-8, x less than or equal to 0. Find the inverse of f(x)

1. anonymous

let f(x)=y y=x^2-8 x^2=y+8 $x=-\sqrt{y+8},$ interchange x and y $y=-\sqrt{x+8},or f ^{-1}\left( x \right)=-\sqrt{x+8}$

2. lisa123

why is x= -sqrt (y+8). Negative? @surjithayer