Question 1152608
answer:

c. {{{f(t)=-3sin(3t)}}}

explanation:

{{{f(t)=-3sin(3t) }}}

periodicity of a {{{sin  (bt + c ) + d= (periodicity -of-sin(t ))/(b)}}}

periodicity of a {{{sin  (t )}}} is {{{2pi}}}

=>periodicity of a {{{sin  (3x  )}}} is {{{2pi/3}}}



{{{drawing( 600, 600, -5, 5, -5, 5,
circle(-2pi/3,0,.1),circle(2pi/3,0,.1),
locate(-2pi/3,0,p(-2pi/3,0)),locate(2pi/3,0,p(2pi/3,0)),
 graph( 600, 600, -5, 5, -5, 5, -3sin(3x))) }}}