I don't believe AutoCAD can draw a 'true' sinewave, but can be made to draw 'close enough for practical purposes' by drawing a polyline fitted or splined between closely spaced points. A freeware lisp routine, file name 'geomcurv.zip' is available at
which draws all different kinds of mathematical curves. Or write your own, you can make the spacing of pline vertices controlled by user, among other things.