# Newtons method. Intersection between graphs.

• Apr 13th 2011, 12:08 PM
Kuma
Newtons method. Intersection between graphs.
Hi.

I have the 2 graphs e^x and 2-x. I want to find out the intersection point using newtons method. My question is how do i know what f(X) is.
• Apr 13th 2011, 12:11 PM
Plato
Quote:

Originally Posted by Kuma
I have the 2 graphs e^x and 2-x. I want to find out the intersection point using newtons method. My question is how do i know what f(X) is.

Let $f(x)=e^x-(2-x)$.
• Apr 13th 2011, 12:14 PM
Kuma
why not the other way around though? How do you determine this.
why cant it be 2-x - e^x
• Apr 13th 2011, 12:19 PM
Plato
Quote:

Originally Posted by Kuma
why not the other way around though? How do you determine this.
why cant it be 2-x - e^x

It does not matter. You could do that.
The root will be the same either way.
• Apr 13th 2011, 12:20 PM
Kuma
Quote:

Originally Posted by Plato
It does not matter. You could do that.
The root will be the same either way.

Thanks. One last thing. So that's the case for any two graphs then? Order does not matter?
• Apr 13th 2011, 12:49 PM
Plato
Quote:

Originally Posted by Kuma
Thanks. One last thing. So that's the case for any two graphs then? Order does not matter?

$0=-0=+0$.