Question 1159849
This transforms a vector through {{{theta}}} degrees in the counterclockwise direction.  Just plug in {{{theta = 60^o}}}:<br>

{{{ (matrix(2,2,cos(theta),-sin(theta),sin(theta),cos(theta))) }}}<br>

{{{ (matrix(2,2,cos(60),-sin(60),sin(60),cos(60)))(matrix(2,1,v1[x],v1[y])) = (matrix(2,1,v2[x],v2[y])) }}}