Monthly Archives: August 2024

Using the Hungarian Algorithm for an Assignment Problem

The following question is from the 2019 ATAR Mathematics Applications Paper – Calculator Free Question 3.

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Filed under Networks, Year 12 Mathematics Applications

Sketching in the Complex Plane Using a TI-nspire CX 11

Let R be the region of the complex plane where the inequalities |z-i|\le2 and |z-\bar{z}|\ge3 hold simultaneously.

First find the Cartesian equations.

Finding the symbols


The conj(z) is found under
Menu – Number – Complex Number Tools – Complex Conjugate

Second, sketch each of the functions.

The section that is shaded twice is our region.

Determine the minimum value of Re(z) in R.

We can find the point of intersection between the circle and the line.

Re(z)=-1.94

Or if you want exact values

Use the Solve Systems of Equations tool – Menu – Algebra – Solve Systems of Equations – Solve Systems of Equations.

Re(z)=-\frac{\sqrt{15}}{2}

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Filed under Complex Numbers, Sketching Complex Regions, TI nspire CX 11

Pythagoras Question

This was a question one of my year 9s had to tackle:

A hemisphere of radius length 5cm is partially filled with water. The top of the hemisphere is horizontal and the surface of the water is a circle of radius 4cm. Find the depth of the water.

ICE-EM Mathematics 9, page 70, question 2

Below is a cross section of the hemisphere

The depth of the water is 5-x

We can find x using the Pythagorean theorem

x^2=5^2-4^2

x=3 (it’s the classic 3-4-5 triangle)

Hence the depth of the water is 2cm.

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Filed under Pythagoras