Two and a half finale questions of mathematical function in senior high school entrance examination (combined into one)

1.y = kx+b(k >； B & gt0)x axis intersection A coordinate (-b/k, 0), Y axis intersection B coordinate (0, b).

Y=bx+k, the c coordinate (-k/b, 0) of the intersection of the x axis and the d coordinate (0, k) of the intersection of the y axis.

Triangle AOD AOD and COB are similar, and they are all right triangles, that is, AO/DO=CO/BO.

|-b/k|/k=|-k/b|/b, that is, b/k 2 = k/b 2, that is, b 3 = k 3, b = k, which is inconsistent with the meaning of the question and does not exist.

If the direction comparison of the corresponding sides of the triangle is allowed, there are

AO/DO=BO/CO，|-b/k|/k=b/|-k/b|，bk= 1

So as long as b and k are reciprocal, there are countless 1, such as y=4x+ 1/4.

y= 1/4x+4

Second, draw a picture.

Suppose a (x 1, 0), b (x2, 0), c (0, -4/3), p ((4/3-a)/2a, -4/3).

AB=CP

x2-x 1=(4/3-a)/2a

square

(x 1+x2)^2-4x 1x2=[(4/3-a)/2a]^2

The value of solution a