Question 748184
We use the general form of the equation to determine parameters

{{{
f(x)=a*cos(omega*x+theta)+f[0]
}}}
{{{
f(x)=-3*cos(4*x+0)+0
}}}


This comparison tells us the following


Period:
{{{
omega=(2 *pi)/T
}}}
so

{{{
T=(2 pi)/omega=(2* pi)/4=pi/2
}}}



Range: 
{{{
f[0]-abs(a)<= x <=f[0]+abs(a)
}}}


which is
{{{
-3<=x<=3
}}}



Amplitude:
{{{
a=abs(-3)=3
}}}






:)