Think of it this way: as you substitute values of theta in, you "arrive" at the y-values "faster", so you're drawing sin(2theta) faster than sin(theta) www.desmos.com/calculator/xrmwysbnlr
is it just when regarding the period of graphs that they can only be stretched in the x axis? Because during my as year in school I recall doing all 4 graph transformations.. where reflection in the x axis for example was y=-f(x)..etc. Am i confusing these for just general graph transformations as i haven't quite covered the graphs and transformations section of your videos yet. Please reply ASAP many thanks.
I don't really understand your question. Trig graphs are periodic and here we're finding the new period of the function after it has been transformed. A stretch parallel to the x-axis will affect the period of the function.
The period of a trig function is important to know when solving trig equations to find all of the solutions, as well as when you need to sketch a transformed curve.
![A-Level Maths: E3-04 [Trig Graphs: State the Period of the Transformed Trig Graph]](http://i.ytimg.com/vi/82PZpq9ua2s/mqdefault.jpg)
![A-Level Maths: E3-04 [Trig Graphs: State the Period of the Transformed Trig Graph]](/img/tr.png)
![A-Level Maths: E3-01 [Trig Graphs: Sketching sin(x), cos(x) & tan(x) from the Unit Circle]](http://i.ytimg.com/vi/PHARBTwF89k/mqdefault.jpg)
Is there a video on calculating the period and the amplitude of a trig function?
Here you are: ruclips.net/video/zteBxrMZiCw/видео.html
y=sin2Theta why does it half it instead of double it ?
Think of it this way: as you substitute values of theta in, you "arrive" at the y-values "faster", so you're drawing sin(2theta) faster than sin(theta)
www.desmos.com/calculator/xrmwysbnlr
is it just when regarding the period of graphs that they can only be stretched in the x axis? Because during my as year in school I recall doing all 4 graph transformations.. where reflection in the x axis for example was y=-f(x)..etc. Am i confusing these for just general graph transformations as i haven't quite covered the graphs and transformations section of your videos yet. Please reply ASAP many thanks.
I don't really understand your question. Trig graphs are periodic and here we're finding the new period of the function after it has been transformed. A stretch parallel to the x-axis will affect the period of the function.
what if there's a function like y=sin(x+a)
That +a is just going to translate the graph left or right, so that won't affect the period
when is this relevant though ?
The period of a trig function is important to know when solving trig equations to find all of the solutions, as well as when you need to sketch a transformed curve.