Hello, i need some help with the following
1) If x,y>0 show that 1/x + 1/y > or equal to 4/(x+y)
2) Using cauchy's inequality, prove that 2(a^3 + b^3 + c^3) greater than or equal to ab(a+b) + ac(a+c) + bc(b+c) greater than or equal to 6abc
Thank you :c
____________________
I have no idea what they teach there because the Cauchy-Schwarz inequality
isn't even in the HSC... I do not see how this benefits students when they can't even use it in the exam.
Remarks: A lot of algebra was rushed. You may consider working through the algebra more slowly.
For the linear algebra version |
a.
b| ≤ ||
a|| ||
b||, simply treat the terms of the sequence as the components of the vectors instead.
Haven't figured out how C-S can be used for the first half yet