How do you graph #y=(cos2x)/2#?

1 Answer
Feb 5, 2015

Start with #y=cos(x)#
graph{cos(x) [-7, 7, -1.5, 1.5]}
Next, to change the argument from #x# to #2x#, we should "squeeze" the graph horizontally by a factor of 2 because, if a point #(a,b)# belongs to a graph of a function #y=f(x)#, a point #(a/2,b)# belongs to a graph of #y=f(2x)#.
graph{cos(2x) [-7, 7, -1.5, 1.5]}
Finally, we have to "squeeze" the graph vertically by a factor of 2 because, if a point #(a,b)# belongs to a graph of #y=f(x)#, a point #(a,b/2)# belongs to a graph of #y=f(x)/2#:
graph{cos(2x)/2 [-7, 7, -1.5, 1.5]}