Math CentralQuandaries & Queries


Hodan, a student:
Describe how you could use your knowledge of Double angle formulas to sketch the graph of each function. Include a sketch with your description.

A) F(x)=sin x cos x
B)F(x)=2 cos2x
C) F(x)= tan(x) / ( 1-tan2x)

Hi Hodan,

Here is a list of the double angle identities:

You'll need to manipulate the fucntions a little bit to subsitute the double angle identity. For example part b)

It will be much easier to graph f(x)=cos2x+1 because it is in stand graphing form now. When graphing trig functions, any coefficient infront of the x will effect the period of the function in the following way

So what is the period length of a double angle identity? How does this effect the appearance of the graph?


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