circuits 2 (sinusoid) ,can you guys please help me?

First learn to draw a sinusoid. How is that done? take a graph sheet and plot degress on X axis and its sine value on Y axis. Thus you get points such as 0,0 followed by (22.5, 0.383), (45, 0.707), (67.5,0.924), (90,1), (112.5,0.924). (135,0.707),(157.5, 0.383), ( 180,0), followed by negative values in same sequence for 180 degrees to 360 degrees. join these and lo and behold, you have a sinusoid!

NEXT: Take degress spacing as 30,60,90, 120 etc and find their sine. make a table with X in degrees in one column, and Y = sin9x) in another column. Plot this, You will again get a sinusoid.

Not take a deep breath and understand v=100cos(400pi t+60 degrees) . here 400pi is omega, and f is 400pi/2pi = 200 Hz. so v is a 100V peak sine with frequency as 200 hz.its period is 5mS, and one period corresponds to 360 degrees. So if you are a wizard you can caculate time instants corresponding to 30 deg, 60 degrees, and so on.

If you consider another waveform say vdash = 100sine(400pi t), that is a sine having zero voltage at zero time (or zero degrees). Its peak will occur as 100 at 90 degrees which is T/4 = 1.25 mS away towards right from origin.

Consider another vdoubledash, =100sine(400pi t +60deg). . this is another sine that leads the vdash by 60 degrees. at origin its value is 100.sin(60). It is something like it has an advantage of 5/6mS. which corresponds to 60 degrees. Its zero would have occurred at -5/6 mS.

Now take two deep breaths and plot v.Note that it is cosine, so take cosine values instead of sine. You will find that cos leads sine by 90 degrees. You may plot first 100 cos(400pit).

How can you be in Circuits 2, if you don't know how to draw a graph?