- #1
Mr Davis 97
- 1,462
- 44
Homework Statement
Let ##\displaystyle f(x) = 3 \left( x + \frac{1}{x} \right)##. Use AM-GM to find the minimum value.
Homework Equations
The Attempt at a Solution
I know how to find the minimum value using calculus: we take the derivative, set it to zero,then find the critical points. Then we can use the second derivative to distinguish between maxima and minima.
However, I am not sure how to use the AM-GM inequality to do this, which is that ##\displaystyle \frac{x+y}{2} \ge \sqrt{xy}## for all non-negative real numbers x and y