+1124 Hi friends,
Please help me with this one:
Prove that \(x^2+2xy+2y^2\) cannot be negative for x, y element of R. Thank you all kindly.
+118667 I'll give you a good hint juriemagic
Can you take it from there ?
\(x^2+2xy+2y^2\\ =(x^2+2xy+y^2)+y^2\\ =?\)
To be honest, before I even thought about it, I graphed it.
https://www.desmos.com/calculator/6czdsarjnn
the graph gave me hints and showed me that this expression could not be negative.
