So you start with an #x# #y# table (t-chart) and then you write numbers in the #x# column. I typically use #-2# through #2#.
Those numbers are your #x# values. The equation is #y = x^2# tells you to take your #x# values individually and square them, giving you your #y# values.
Then you input the #y#-values into the chart. #-2# and #2# should have the #y#-value of #4#,
#-1# and #1# should be #1#, and zero is zero. Once you have your points (an x-y pair is a point), just graph the points and draw a line through them like this:
graph{x^2 [-10, 10, -5, 5]}
Hope this helps!