Square of parabola y = x, section line y = x, the length of line segment is

Square of parabola y = x, section line y = x, the length of line segment is

y=x
Substituting
x²=x
x=0,x=1
So the intersection points (0,0), (1,1)
So the line length = √ [(1-0) & sup2; + (1-0) & sup2;] = √ 2