1)

x？ -x+m=0 has no negative root.

So:

m=-x？ +x

Equivalent to a straight line y=m and a parabola f(x)=-x? The abscissa of the +x intersection.

Draw a chart to show when 0

So: 0

2)

x？ -3x+a=0 has two roots greater than 1

Parabola f(x)=x? -3x+a opening is upward, and the symmetry axis x=3/2.

Then f (1) =1-3+a = a-2 >; 0

Solution: a>2

Discriminant =(-3)? -4a & gt； =0

Solution: a

So: 2

x？ -2x-8 & lt； =0

(x-4)(x+2)& lt； =0

-2 & lt； = x & lt=4

So: A ∩ B = (2 2,9/4)