solve sum of square roots using a single functiom using Newton's Method I have to estimate $n= \sqrt{3} + \sqrt{7}$ using Newton's Method of approximation but I have to determine a single function which can be used to estimate $n$. 
P.S: The function should not involve radical expressions (nth root of constants or variables)
So, I just need to know what the single function is. I can solve the rest myself
Thanks!

HINT  Newton's method is a root finder, meaning given a function $f(x)$ it computes the root of $f(x)$, i.e. the special argument $\bar{x}$ such that $f(\bar{x}) = 0$.
You need for Newton's Method to find $\sqrt{3} + \sqrt{7}$. Can you find a function $f(x)$, which will have a root at this magic place?
