Question 316629
Just like any other function.
Pick some x points, solve for y, graph the x-y pairs and draw a line connecting all of the points. 
For {{{x=0}}}, {{{y=x^2=0}}} :(0,0)
For {{{x=1}}}, {{{y=x^2=1}}}:(1,1)
For {{{x=2}}}, {{{y=x^2=4}}}:(2,4)
For {{{x=3}}}, {{{y=x^2=9}}}:(3,9)
For {{{x=-1}}}, {{{y=x^2=1}}}:(-1,1)
For {{{x=-2}}}, {{{y=x^2=4}}}:(-2,4)
For {{{x=-3}}}, {{{y=x^2=9}}}:(-3,9)
{{{drawing(300,300,-5,5,-2,10,grid(1),
circle(0,0,.2),
circle(1,1,.2),
circle(2,4,.2),
circle(3,9,.2),
circle(-1,1,.2),
circle(-2,4,.2),
circle(-3,9,.2),
graph(300,300,-5,5,-2,10,0))}}}
.
.
.
Now connect each point to the next with a line. 
.
.
.
{{{drawing(300,300,-5,5,-2,10,grid(1),
line(0,0,1,1),
line(0,0,-1,1),
line(1,1,2,4),
line(2,4,3,9),
line(-1,1,-2,4),
line(-2,4,-3,9),
circle(0,0,.2),
circle(1,1,.2),
circle(2,4,.2),
circle(3,9,.2),
circle(-1,1,.2),
circle(-2,4,.2),
circle(-3,9,.2),
graph(300,300,-5,5,-2,10,0))}}}
.
.
.
The more points you choose the smoother your graph will be. 
.
.
.
{{{drawing(300,300,-5,5,-2,10,grid(1),
line(0,0,1,1),
line(0,0,-1,1),
line(1,1,2,4),
line(2,4,3,9),
line(-1,1,-2,4),
line(-2,4,-3,9),
circle(0,0,.2),
circle(1,1,.2),
circle(2,4,.2),
circle(3,9,.2),
circle(-1,1,.2),
circle(-2,4,.2),
circle(-3,9,.2),
graph(300,300,-5,5,-2,10,x^2))}}}