It started with a tweet!

Sine curve & transformations

I noticed a tweet from Darren Kuropatwa..
DK tweet1

Here is what Darren was referring to, a video made by Desmos on exploring the sine function:

Sine function with sliders

Sine function created on Desmos by Darren Kuropatwa

Darren has recreated that graph here.

Now I rather like that and thinking it would be useful for my revision session this week with a GCSE (UK age15-16) class, decided I would simplify it so it was more suitable for my students. I changed  the units to degrees and restricted the transformations more so it was more in line with our specification (these students are studying for a second GCSE in Mathematics – AQA Further Mathematics level 2).

Along came Desmos having seen the Twitter conversation..
Desmos tweet

and look at the awesome graph Desmos created which shows a sine curve and a transformed curve clearly illustrating how each point is changed.

We could for example translate the curve 2 units parallel to the y axis:
sine curve and translation

Using the slider for angle we see very clearly that each y coordinate is increased by 2.

Brilliant!

Thank you Desmos (and Darren!)

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