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Rotation problem of mathematical linear function
Solution: (1) as shown in figure 1, the passing point b is BD⊥x axis, and the vertical foot is D.

∠∠BCD+∠ACO = 90,∠AC0+∠OAC=90,

∴∠BCD=∠CAO,

∠∠BDC =∠COA = 90,CB=AC,

In δ△BDC and δ△COA,

∠BCD=∠CAO∠BDC=∠COA=90 BC=AC,

∴△BDC≌△COA(AAS),

∫ The linear function y=-2x+2 intersects the Y axis at point A and the X axis at point C,

∴ The coordinates of point A are (0,2), and the coordinates of point C are (1, 0).

∴BD=OC= 1,CD=OA=2,

∴ The coordinate of point B is (3,1);

(2) In Rt△AOB, OA= 1, OB=2, and from Pythagorean theorem, AB = 5.

∴S△ABC= 12AB2=52.

Let the analytical formula of BC line be y=kx+b, ∫ b (0,2), c (3, 1),

∴b=23k+b= 1,

The solution is k=- 13, b=2,

∴y=- 13x+2.

Similarly, the analytical formula of straight line AC is: y = 12x- 12.

As shown in the answer sheet 1,

Let the straight line L intersect BC and AC at points E and F respectively, then ef = (-13x+2)-(12x-12) =1