perplexus.info :: Just Math : Three numbers

Three numbers (Posted on 2003-11-17)

If x, y and z are real numbers such that: x + y + z = 5 and xy + yz + zx = 3, what is the largest value that x can have ?

No Solution Yet Submitted by Ravi Raja

Rating: 3.7500 (4 votes)

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another solution

| Comment 10 of 22 |

x + y + z = 5
x^2 + y^2 + z^2 + 2xy + 2yz + 2zx = 25
2xy + 2yz + 2zx = 6
x^2 + y^2 + z^2 = 19
x max = √19

sorry, something wrong.
Edited on November 18, 2003, 7:54 am

Posted by retiarius on 2003-11-18 07:39:35

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