Question: plot(cos(2*x^2)) doesn't look right

When I plot(cos(2*x^2)) the plot doesn't look right.  The graph area between -7 and -8 jumps and similarily on the positive x-axis.  It doesn't appear to affect values just the visualization of graphs.  If you plot(cos(2*x^2),x=-7..-8) the graph is fine. 

I find graphing certain functions in maple to not be so crisp and clean.  Not sure why that is.  I haven't tried this in the classic interface yet as I mainly play around in the standard interface.  If you plot it out you'll see what I mean.  The maximums and minumums also aren't uniform across the range, they seem to cut short at times and look jagged.  Is maple working on a fix or maybe I've just forgotten about something, I know when I work on AutoCAD and zoom in if I don't set fast zooms to a high value I'll get circles looking like hexagons.  Maybe with maple there's a similar setting. 

Anyone else experiencing the same effect?  Why does it do that?