question: void xrot ( double theta ) { theta *= ( pi / 180 ) ; double ct = Math . cos ( theta ) ; double st = Math . sin ( theta ) ; float Nyx = ( float ) ( yx * ct + zx * st ) ; float Nyy = ( float ) ( yy * ct + zy * st ) ; float Nyz = ( float ) ( yz * ct + zz * st ) ; float Nyo = ( float ) ( yo * ct + zo * st ) ; float Nzx = ( float ) ( zx * ct - yx * st ) ; float Nzy = ( float ) ( zy * ct - yy * st ) ; float Nzz = ( float ) ( zz * ct - yz * st ) ; float Nzo = ( float ) ( zo * ct - yo * st ) ; yo = Nyo ; yx = Nyx ; yy = Nyy ; yz = Nyz ; zo = Nzo ; zx = Nzx ; zy = Nzy ; zz = Nzz ; }
target:  rotate theta degrees about the x axis 