√4−2√3 can be expressed as a+b√c, where a, b, and c are intergers and c is squarefree. Find a+b+c.
Any help is appreciated!
a+b√c=√4−2√3
We can easily speculate the c = 3 (what else could c be equal to, 17!?).
a+b√3=√4−2√3
We can safely square both sides of the equation...
(a+b√3)2=4−2√3
Open up parenthesis: a2+2ab√3+3b2=4−2√3
Then we can see that the root 3 part corresponds to the root 3 part in the equation since a and b are integers:
2ab√3=−2√3
ab=−1
From earlier, we also obtained:
a2+3b2=4
How can you take it from here to find a and b? Good luck...