for the first one pi= 180 degrees, therefore it is asking for a normal sine graph between 0 and 360 degrees however it wants the axis marked in radians e.g. pi=180 degrees,

2pi=360 degrees and so on.

for the second one 2sinx=-1

therefore sinx= -0.5

therefore x= 210, 330 degrees and remembering that pi=180

x= 7/6 pi or 11/6 pi

does this help??