maximum minimum

Photo Credit: mysza831

One of the applications of Differentiation is to determine the type of stationary point. This application is common in maximum and minimum problems.

There are two ways to go about finding the type of stationary point. The more frequently used method is through Second Derivative (Watch the video here). (d^2y/dx^2)

However, I'm not going to discuss on that method. Instead I want to share with you on the less popular method which is First Derivative. The reason: I have observed that last 2 years, questions appearing in the GCE 'O' level Additional Mathematics were less commonly seen, least expected and definitely more nerve breaking for candidates who aren't prepared.

Let's take a look at how First Derivative is applied. [Read more...] about A-Math: Type of Stationary Point through First Derivative

Qn2
A closed box with a square base of length x and height h, is to have a volume, F, of 150m^3. The material for the top and bottom of the box costs $2 per square metre, and the material for the sides of the box costs $1.50 per square metre. Fnd the value of x and h, correct to 3 decimal places, if the total cost of the materials, C is to be a minimum.
Qn3
A viscous liquid is poured onto a flat surface. It forms a circular patch which grows at a steady rate of 6cm^2/s. Find,
a) the radius r, in pie, of the patch 24 seconds after pouring has commenced.
b) the rate of increase of the radius at this instant, correct to 2 decimal places.

Done reading the qns? Do and see if your answers are correct!

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