# Thread: integration, calculating surface where f(x):y^2 = ....

1. ## integration, calculating surface where f(x):y^2 = ....

Hi, I have two functions

f(x): y^2 = 2x + 4
g(x): y = x^2

Now, I need to calculate the surface using those 2 functions.

I know if f(x) were y = 2x + 4, you would simply do h(x) = f(x) - g(x) and then integrate it from/to the intersecting points

But thanks to f(x) being a function using y^2, I am completely lost.

Thanks a lot in advance for helping!

2. ## Re: integration, calculating surface where f(x):y^2 = ....

$y^2=2x+4$
$\mid y\mid=\sqrt{2x+4}$
and this can be result in two functions
$y=\sqrt{2x+4}\;\;\;\;y^*=-\sqrt{2x+4}$

now u have three functions, can you continue?

3. ## Re: integration, calculating surface where f(x):y^2 = ....

got it, thanks!