# How can I plot the point of $y=\sin(x)$?

I am taking an online trig course so I don't have the luxury of asking for help when I don't understand something. How can I plot $y=\sin(x)$?

-
Are you working in degrees or radians? – Mark Bennet Feb 12 '12 at 19:09

Sine (as well as cosine, tangent or cotangent) is no straight line or circle, so if you're drawing on paper, I don't think there are tools for plotting it perfectly correct, unless you have some specials sine-function rulers or something. You just draw equal waves and mark the period of $\pi/2, \pi, 3\pi/2, 2\pi$ on the $x$-axis, and mark the highest/lowest value of sine $1$/$-1$ on $y$-axis. (If that's what you were asking, because I'm not sure if I clearly understand the question.)

-

You will see how the sine is the "dynamic" plot of the point moving along the unit circle. You can then plot it by marking "easy" angles in your line (i.e 30º, 45º, 60º, 90º, etc..) and then contructing the angle in the circle. Then find the intersection between the hegiht of the point in the circle and the point in you line. Use this as a help. Make sure you look at the recommended videos to get a better idea.

I made you a little GeoGebra applet you can use to see it.

-

The way I usually graph a sine wave is to draw a wave, then label the points that are easy $0, \pi/2, \pi$ and so on. It is easiest to explain in person. A local community college probably has a free tutoring center you can use.

Also here is a video from Khan Academy on how to graph a sine wave. http://www.khanacademy.org/video/graph-of-the-sine-function?topic=trigonometry

-

If you are just looking for a graph of the function, type "plot y = sinx" into wolframalpha.com. If you want to learn to graph it manually, study the output of the Wolfram|Alpha query.

-