## Welcome to H3 Maths

Blog Support for Growing Mathematicians

## Archive for June, 2013

### Forever blowing bubbles, mathematically speaking…

June30

Robert I. Saye, a PhD student in applied mathematics, and James A Sethian, professor of mathematics at University of California, Berkeley, have come up with a set of mathematical equations to describe how the bubbles in foam rearrange themselves. The problem with describing foams mathematically has been that the evolution of a bubble cluster a few […]

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June29

The field of advertisements is a very fruitful one for growing mathematicians. For example, if you hear the advert, “90% of women use xxxx brand of shampoo” you would be right in thinking that 90% of ALL women use the xxxx brand, right? No, of course not! Perhaps only 10 women were surveyed and, of […]

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### When average is not average…

June27

“A survey of six students in my class shows that the average pocket money earned is \$28 each week.” But, wait a minute! Five of these students earn less than the average! Imagine how they feel? What is going on with this survey data?Let’s have a closer look… Yes, the data shows what is going […]

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### The Time Speed Distance Triangle

June27
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### Wimbledon Update – 7 from 7

June27

Yes, it was an unbelievable day at Wimbledon yesterday with Seven former number one-ranked players crashing out in the seven hours of play between 1pm and 8pm. Now, if we take out the mathematics from the sentence above we read, “Yes, it was an unbelievable day at Wimbledon yesterday with former number-ranked players crashing out in the hours of […]

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### Game, set, match – Wimbledon Math

June27

Wimbledon! This great tennis tournament started on June 22. This year, 128 women and 128 men will battle it out for the women’s and men’s singles titles over a two week period. “In each round of the singles events the players are paired off, and the winners of these matches proceed onto the next round. […]

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### Echo..echo..echo

June24

“A snap of a finger, a handful of scattered microphones and a computer algorithm are all it takes to create an accurate three-dimensional map of a room, say Swiss and US researchers. The method, described recently in the US journal the Proceedings of the National Academy of Sciences, measured the distance between echoes to create maps of […]

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### More Number Crunching…

June23

200 CARS: The number that General Motors supplied for destruction in the final battle scene in the first Transformers movie. 38 PER CENT: The average rating of all three Transformers on the Rotten Tomatoes review website. 4 BILLION: Revenue in \$US for the three Transformers films. Source: NZ Herald

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### y=mx+c

June22

Yes, dear mathematicians, the above equation is the general one for a straight line, where “m” is the gradient or slope (which equals the rise divided by the run). In this image the gradient = rise/run which equals 5/7 or 0.714 (3d.p.) But, why do we use “m” for the gradient or slope? I was […]

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### Perfect Squares

June19

Perfect Squares are really interesting algebraic patterns, such as the expansion of (a+b)(a+b) and its cousin, (a-b)(a-b). For the gowing mathematician they are essential to search out and recognise. There are always really exciting mathematical discoveries to be made – you just have to look for them (or ask your teacher). This is what is happening […]

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#### Post Support

The graph on the left (Coronavirus) is for a time period of 30 days, while the one on the right (SARS) is for 8 months! Very poor graphical comparison and hardly relevant, unless it is attempting to downplay the seriousness of the coronavirus?

10 x 9 x 8 + (7 + 6) x 5 x 4 x (3 + 2) x 1 = 2020

NCEA Level 2 Algebra Problem. Using the information given, the shaded area = 9, that is:
y(y-8) = 9 –> y.y – 8y – 9 =0
–> (y-9)(y+1) = 0, therefore y = 9 (can’t have a distance of – 1 for the other solution for y)
Using the top and bottom of the rectangle,
x = (y-8)(y+2) = (9-8)(9+2) = 11
but, the left side = (x-4) = 11-4 = 7, but rhs = y+? = 9+?, which is greater than the value of the opp. side??
[I think that the left had side was a mistake and should have read (x+4)?]