Question 121954

The general form of cosine is:

{{{y = Acos(Bx + C) + D}}}

where the period {{{T=2pi/B }}}
 
So for the trig function {{{f(x)=3 - 2cos(3x+pi)}}} which also looks like {{{f(x)= - 2cos(3x+pi)+3}}}. Notice how {{{3x}}} matches up with {{{Bx}}}, so {{{Bx=3x}}} which means {{{B=3}}}
 
{{{T=2pi/3 }}} Now simply plug in {{{B=3}}} into the period formula
 

So the period is {{{T=2pi/3 }}}
 

So the answer is A)