(1) Turn the function into a vertex: y= 1/2(x- 1)-9/2, ∴ vertex (1, -9/2) axis of symmetry x= 1.

When y=0, 0= 1/2x? -x-4 Solve the intersection of x 1=4 x2=-2 ∴ and X axis and (4,0) (-2,0).

When x=0, y=-4. The ∴ intersection point with the Y-axis sum (0, -4)

Then draw a sketch, just trace the three points and vertices of the coordinate axis and connect them.

(2) when x > 1, y increases with the increase of x, and when x < 1, y decreases with the increase of x.

When x= 1, the minimum value of y =-9/2.

At least give me some reward!