How do you graph #y=2cos(1/2x)#?

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Answer 1 · 2017-12-10T10:30:45

As shown below:

The first thing we must consider is what tranformations #cosx# must undergo to reach #2cos(1/2 x )#

First we stretch #cosx# by a scale factor of 2 in the #y# direction, to yield # 2cosx #

Then Stretch by a scale factor of #2# to yield, #2cos(1/2 x )#

#cosx#: graph{cosx [-4.213, 4.44, -2.022, 2.305]}

#2cosx: # graph{2cosx [-4.213, 4.44, -2.022, 2.305]}

#2cos(1/2 x ) :# graph{2cos(1/2 x ) [-8.54, 8.766, -4.184, 4.47]}

Has roots #(pm pi , 0 ) # on this graph