Question 1078935
{{{graph(300,300,-8,8,-1,6,2*cos(x+(2*pi/3))+3)}}}
At -2*pi/3, the cos () will be at the normal start, so it will be 1.
The 2 doubles the amplitude to +/- 2 over the baseline.
The +3 shifts the whole function upward 3 units.
It is the cosine function, twice as high, shifted upward 3, so it goes between 1 and 5, not -1 and 1, and it starts at -2 pi/3, which numerically is a little more than -2 radians, and goes to 4 pi/3, or about 4 radians.
At x=0, it is the cosine of 2pi/3, which is (-1/2), so it will be doubled and added to 3, and the value is 2.
The minimum will be pi radians later or at pi/3 or about 1, and its value will be 1. 
It crosses 3 again when the cosine is 0, which occurs at 3 pi/2 normally and here the difference between 3pi/2 and 2pi/3, or 5 pi/6, or between 2.5 and 3.
It reaches 5 again 2 pi after the start, which is 4 pi/3, or almost 4.