1. ## Inverting fucntions

Having trouble inverting these functions, I get stuck when trying to solve for y,

$y=x+\sqrt{x}$
and
$y=\frac{1-\sqrt{x}}{1+\sqrt{x}}$

2. Hello !
Originally Posted by Robb
Having trouble inverting these functions, I get stuck when trying to solve for y,

$y=x+\sqrt{x}$
and
$y=\frac{1-\sqrt{x}}{1+\sqrt{x}}$
$(\sqrt{x})^2+\sqrt{x}-y=0$
$u^2+u-y=0$

Now solve this quadratic equation for u. The root has to be positive. So following the values of y, you'll have two expressions for u.
Then substitute get back to $x=u^2$
And you're done =)

For the second one :
$y(1+\sqrt{x})=1-\sqrt{x}$
$y+y\sqrt{x}=1-\sqrt{x}$

$\sqrt{x}(y+1)=1-y$

$\sqrt{x}=\frac{1-y}{1+y}$

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