{"id":2621,"date":"2015-04-04T12:15:16","date_gmt":"2015-04-04T11:15:16","guid":{"rendered":"https:\/\/mathedup.co.uk\/?p=2621"},"modified":"2015-08-03T20:41:19","modified_gmt":"2015-08-03T19:41:19","slug":"transforming-graphs","status":"publish","type":"post","link":"https:\/\/www.mathedup.co.uk\/transforming-graphs\/","title":{"rendered":"Transforming graphs"},"content":{"rendered":"
Now, don’t get me wrong, I live in the real world and I completely get that sometimes we just need a way of remembering how to do stuff. But over the past however many years, when I have picked up a year 12 AS maths class, the thing that has annoyed me the most is their understanding of transforming functions from GCSE. They often have no idea what the function notation means, how it works nor how it relates to the graph. This leads to difficulty for some students later on when it comes to composite transformations and getting a real understanding of solving trig equations.\u00a0I do understand, to a certain extent, that it is usually one of the last few things taught at the end of year 11 and is often rushed as a result but in my opinion, if it’s worth teaching, it’s worth teaching well..<\/p>\n
This year, for the first time in a number of years, I have had the opportunity to work with a higher ability year 11 class (I’m usually a C\/D bordeline crusader). I have an enthusiastic set 2\u00a0of which many plan to do A-Level maths.\u00a0Having not taught a ‘proper’ higher group for a while, I was anxious about transformations of functions coming up on the scheme of work as\u00a0I knew I wanted to do it properly, but I was unsure of what approach to take. I had an IT room lesson which I thought would be the perfect opportunity for them to play around with some graphs on Desmos and get a feel for what was going on. I structured the lesson using this worksheet<\/a> and I had got them to write everything up in their exercise books.<\/p>\n Desmos: A jolly good bit of graphing software<\/p><\/div>\n There was a great buzz in the room as they worked and some fantastic discussions could be heard throughout the lesson. It was one of those lessons, where as a teacher, there was very little to do and the students were fully engaged throughout (who doesn’t love using Desmos!). Towards the end of the lesson as I went around the room to check their understanding, I heard someone say those words: “if it’s in the brackets, just do the opposite”. My heart sank a little.\u00a0As I questioned them further, it became apparent that they had noticed what happens, but had no idea why it was happening. They were able to predict what would happen when I showed them a function and knew what it would look like but their overall understanding was fragile at best. I do believe there was value in the activity, however, I felt that there was still some learning that needed to take place before moving on..<\/p>\n I put together this lesson as an introduction to function notation<\/a> and tried to develop a\u00a0strong understanding of why the notation was useful and what it means. I extended it to composite functions, which\u00a0they seemed to really enjoy!<\/p>\n<\/a>