Another function expression y=ax? +bx+c, then according to the meaning of the question, there is

0= 16a-4b+c

0=4a+2b+c

-4=c

∴a= 1/2

b= 1

c=-4

∴y= 1/2x？ The ordinate of +x-4 ∴ M is 1/2m? +m-4

MN⊥BO passing through M is N, Ba passing through E or its extension line, MH⊥BA passing through H.

∫ao = bo = 4 ao⊥bo

∴∠AB0=45 AB=4√2

∴∠ben=45 ∴en=bn=4-y=8- 1/2m？ -∴ me = Mn-en = m-en =1/Mr 2m? +2m-8

∴∠MEH=∠BEN=45

∴∠MEH=∠HME=45

∴MH=﹙√2/2﹚ME

s⊿= 1/2×ab×mh= 1/2×﹙4√2﹚×﹙√2/2﹚﹙ 1/2m？ +2m-8﹚=m？ +4m- 16

If point P is a moving point on a parabola and point Q is a moving point y=-x on a straight line, judge how many positions can make a quadrilateral with points P, Q, B and O as vertices, and directly write the coordinates of the corresponding point Q..

Obviously ∠ BOQ = 45 or ∠ BOQ = 135 If ∠ BOQ = 45, it is obviously irrelevant.

Then ∠ BOQ = 135, Q is in the second quadrant, ∠ PBO = 45, then P is on AB, BO=OP=4∴ There is a position, the quadrilateral with the vertices of P, Q, B and O is a parallelogram, and P coincides with A. Q(-4