The graph in black is 1/4sinx, as sinx+1/4 is an upwards translation, which this equation does not have.
A is half way through the period, which, since it isn't altered, is 2π long. Therefore, being halfway through the period, it is just π.
B is 3/4 of the way through the period, so it is 3π/4
C is the bottom of the 1/4sinx wave, which is 1/4 the height of a standard sine wave at the bottom. This means it is -1*1/4, or -1/4.
D is the top of the sinx+1/4 wave, or 1+1/4, so the D is 1 1/4.
Hope this helps!
