A typical graph of #y=sinx# has domain for all values of #x# and range is from #[-1,1]#.
It is a cyclical curve and repeats after every #2pi#, hence its period is #2pi#.
It's value is #0# at each #npi#, it touches a maximum value of #1# at each #2npi+pi/2# and a minimum value of #-1# at each #2npi-pi/2# (where #n# is an integer).
It appears like graph{sin(x) [-10, 10, -2, 2]}
If we draw the graph of #y=2sin(x+pi)#, the range will be doubled due to multiplier #2# and will be #[-2,2]#.
However, the graph will be shifted by #pi# and hence minimum value will be #-2# at each #2npi+pi/2# and a maximum value of #-2# at each #2npi-pi/2# (where #n# is an integer). But the function will continue to have value #0# at each #npi#.
As the period of curve is #2pi#, it does not matter whether you say it has shifted by #pi# to the left or right.
The graph of #2sin(x+pi)# appears like graph{2sin(x+pi) [-10, 10, -2, 2]}
