glittergal96
Active Member
- Joined
- Jul 25, 2014
- Messages
- 418
- Gender
- Female
- HSC
- 2014
Re: HSC 2015 4U Marathon
ii) Expand![](https://latex.codecogs.com/png.latex?\bg_white \frac{1}{2}((x-y)^2+(x-z)^2+(y-z)^2)\geq 0.)
iii)![](https://latex.codecogs.com/png.latex?\bg_white 3LHS=(a^2+b^2+c^2)(a+b+c)-a^2(b+c)-b^2(a+c)-c^2(a+b)\\ \geq (ab+ac+bc)(a+b+c)-a^2(b+c)-b^2(a+c)-c^2(a+b)=3abc.)
i) 0, as these are roots of the polynomial.
ii) Expand
iii)