me.parashar wrote:thanks christiancryan. I too, answered the question wrong (marked obvious A). And the way you explained the question, I now know a very important concept of working the maxima-minima without the differential, and the beauty is that the concept can be used everywhere from number system to coordinate geometry.

good.

also, don't forget that the only mathematics required for this exam is the stuff up to and including high-school algebra and geometry. therefore, if you find yourself employing calculus, trigonometry, etc. in an attempt to solve one of these problems, you can rest assured that you are overcomplicating the issue.