Special topic: computational problems; Query type.
Analysis: (1) Because △AOB is an isosceles right triangle and A (4 4,4) is AE⊥OB in E, the coordinates of point B can be obtained;
(2) Let AE⊥OB be in E, DF⊥OB be in F, and verify △ DFC △ CEA. Then, according to the equivalent transformation, it is proved that △AOB is an isosceles right triangle, and then the degree of △ ∠AOD can be obtained;
(3) The equation holds. It is easy to prove △EAN≌△AE⊥OB by intercepting AN=OF, even en. Then it is proved that △ nem △ FEM has AM-MF=OF according to the angle relation, and the equation is established. Solution: (1)
∫A(4,4),
∴OE=4,
∵△AOB is an isosceles right triangle, while AE⊥OB,
∴OE=EB=4,
∴OB=8,
∴b(8,0);
(2) Let AE⊥OB be in E, DF⊥OB be in F,
△ ACD is an isosceles right triangle,
∴AC=DC,∠ACD=90
That is, < ACF+< DCF = 90,
∫∠FDC+∠DCF = 90,
∴∠ACF=∠FDC,
∠∠DFC =∠AEC = 90,
∴△DFC≌△CEA,
∴EC=DF,FC=AE,
∫A(4,4),
∴AE=OE=4,
∴FC=OE, that is, +EF=CE+EF,
∴OF=CE,
∴OF=DF,
∴∠DOF=45,
∫△AOB is an isosceles right triangle,
∴∠AOB=45,
∴∠aod=∠aob+∠dof=90;
Method 1: the extension line of CK⊥x axis intersecting OA is at K,
Then △OCK is an isosceles right triangle, OC=CK, ∠ k = 45,
∫△ACD is isosceles Rt△,
∴∠ACK=90 -∠OCA=∠DCO,AC=DC,
∴△ACK≌△DCO(SAS),
∴∠DOC=∠K=45,
∴∠aod=∠aob+∠doc=90;
(3) (AM-MF)/OF= 1 is established for the following reasons:
Intercept AN=OF, even en on AM.
∫A(4,4),
∴AE=OE=4,
∵∠ ean =∠ eof = 90,AN=OF,
∴△EAN≌△EOF(SAS),
∴∠OEF=∠AEN,EF=EN,
And ∵△EGH are isosceles right triangles,
Geh = 45, that is, OEF+OEM = 45,
∴∠AEN+∠OEM=45
∫∠AEO = 90 degrees,
∴∠NEM=45 =∠FEM,
EM = EM once again,
∴△NEM≌△FEM(SAS),
∴MN=MF,
∴AM-MF=AM-MN=AN,
∴AM-MF=OF,
Namely (am-MF)/of =1;
Method 2: intercept ON=AM, EN, MN,
Then △ EAM △ eon (SAS), EN=EM, ∠NEO=∠MEA,
That is, ∠NEF+∠FEO=∠MEA, and ∠ MEA+∠ MEO = 90,
∴∠ NEF+∠ FeO+∠ MEO = 90, while ∠ FeO+∠ MEO = 45,
∴∠nef=45 =∠mef,∴△nef≌△mef(sas),∴nf=mf,
∴AM=OF=OF+NF=OF+MF, that is, (am-MF)/of = 1.
(1) is the 2B point coordinate of your problem, and (2) is the AOD degree of your problem 1. Ask me if you don't understand.
I have done this problem, and there is another 1 answer.
Title: As shown in the figure, in the plane rectangular coordinate system, △AOB is an isosceles right triangle, A (4 4,4).
(1) Find the coordinates of point B;
(2) If C is the moving point on the positive semi-axis of X axis, take AC as the right angle to make an isosceles right angle △ACD, ∠ ACD = 90, or even OD, and find the degree of ∠AOD;
(3) When the intersection point A intersects with E as the vertical line of the Y axis, F as a point on the negative semi-axis of the X axis, G as a point on the extension line of EF, EG as a right-angled side as an isosceles Rt△EGH, and intersection point A as the vertical line of the X axis intersects with EH at M point or even FM point, does the equation = 1 hold? If yes, please prove it; If not, explain why.