Hello, I need to find the inverse function (finding f^-1) of f(x)= sqrt[3-x]. So I figured y = sqrt[3-x] then solve for x to get x = 3- y^2 (?) when I graph it does not look like the inverse.
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What you did is half correct. You just have to switch the y and the x to get the inverse function.
Originally Posted by Chop Suey What you did is half correct. You just have to switch the y and the x to get the inverse function. Originally Posted by 2clients Hello, I need to find the inverse function (finding f^-1) of f(x)= sqrt[3-x]. So I figured y = sqrt[3-x] then solve for x to get x = 3- y^2 (?) when I graph it does not look like the inverse. As Chops mentioned, just swap the x and y values of the function: $\displaystyle y=\sqrt{3-x}\rightarrow x=\sqrt{3-y}$ Then solve for y to find $\displaystyle f^{-1}(x)$. --Chris
Don't forget the restriction on the domain of the inverse: $\displaystyle y = \sqrt{3-x} \geq 0$ meaning that when you interchange x's and y's, then the 'new' x is greater than or equal to 0.
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