-2cos(2/3x-pi/3) I need to describe the sequence of tranformations from the parent fuction cos(x)

Question

anonymous · Answer

you mean you have to graph it by graph the parent function cos?

anonymous · Answer

i have to describe, sequentially, the changes to g(x)=cos(x) that gives                                 f(x) = -2cos(2/3x-pi/3) and what each changes means.

anonymous · Answer

ok, well prepare for a long process. do you want to know or just take steps?

anonymous · Answer

i have the first step -2*g(x) is a vertical stretch and reflection in x-axis

anonymous · Answer

not that. you MUST start at cos x

anonymous · Answer

tell me with cos x, what is the amplitude and period?

anonymous · Answer

amp is 2 and period is 3pi
 
i think

anonymous · Answer

oh, no, friend, to cos x , amplitude is |1| and period is 2pi

anonymous · Answer

the graph is |dw:1367182855513:dw|