Understanding Inequalities: Part II Question | Need Help?

[synkk]

I need help with the second part, I've managed to get through all of the part (i), but I have no idea where to really start with part (ii), any hints to start me off and I'll keep posting how I'm doing.

thanks

 

[tiny-tim]

hi synkk!

(i don't know whether this works , but …)

i'd try rewriting it as a + b + c ≥ 3abc

 

[dirk_mec1]

Hint: the last equality can be rewritten as:
$$\frac{trs^2 + rst^2+ tsr^2}{rst}$$