needimprovement Posted August 5, 2010 Share Posted August 5, 2010 This equation was solved by great mathematician Ramanujan. It's your turn to solve this equation: √X + Y = 7 X + √Y = 11 Solve it.. prove it... Link to comment Share on other sites More sharing options...
insane_alien Posted August 5, 2010 Share Posted August 5, 2010 it does not take a great mathemaician to do simulataneous equations. Link to comment Share on other sites More sharing options...
Mr Skeptic Posted August 5, 2010 Share Posted August 5, 2010 Looks to me more like a 4th order polynomial. Link to comment Share on other sites More sharing options...
Zolar V Posted August 5, 2010 Share Posted August 5, 2010 lol Link to comment Share on other sites More sharing options...
D H Posted August 5, 2010 Share Posted August 5, 2010 (edited) Looks to me more like a 4th order polynomial. But only one of the four solutions to that 4th order polynomial works in the sense that the square root symbol means the principal value. Hint: This one sensible solution has integer values of x and y. Edited August 5, 2010 by D H Link to comment Share on other sites More sharing options...
DJBruce Posted August 5, 2010 Share Posted August 5, 2010 Here is my answer to the question: A quick inspection of the two equations shows that (9,4) is a solution to that equation. [math]Let: x=9, y=4[/math] [math]\sqrt{9}+4=3+4=7[/math] [math]9+\sqrt{4}=9+2=11[/math] To be honest I didn't really do any algebraic work. I knew that x and y must be positive integer, and more than likely perfect squares. This means y must be less than 7. Since you only have to check the perfect squares y is either 4 or 1. Likewise, x must be less than 11, and since I am assuming x and y are perfect squares you only have to check 9, 4, and 1. Quickly looking at these possible solution sets gives one the answer that x=9, y=4. Link to comment Share on other sites More sharing options...
Sisyphus Posted August 5, 2010 Share Posted August 5, 2010 Here is my answer to the question: Indeed. The flaw in the problem is that the answer is too obvious before you formally solve it. Narrowing down to sensible guesses and using trial and error is a shortcut I've often used, but here there is exactly one sensible guess. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now