It is known that the image of the function y = KX + m intersects with the opening downward parabola y = ax & # 178; + BX + C at two points a (0,1) B (- 1,0) (1) Find the analytic expression of the function y = KX + M (2) If there is an intersection C between the parabola and the x-axis, and the length of the line AC is the root 5, the analytic expression of the quadratic function y = ax & # 178; + BX + C is obtained

It is known that the image of the function y = KX + m intersects with the opening downward parabola y = ax & # 178; + BX + C at two points a (0,1) B (- 1,0) (1) Find the analytic expression of the function y = KX + M (2) If there is an intersection C between the parabola and the x-axis, and the length of the line AC is the root 5, the analytic expression of the quadratic function y = ax & # 178; + BX + C is obtained


(1) the image of ∵ function y = KX + m is solved by a (0,1) B (- 1,0) two points ∵ M = 1, - K + M = 0 to get k = 1, M = 1 ∵ the first-order function is y = x + 1 ∵ OA = | 1 | 1, CA = √ 5, ∠ AOC = 90 °, OC = √ (AC & # 178; - OA & # 178;) = √ [(√ 5) &# 178; - 1 & # 178;] = 2, that is, the abscissa of C is 2 or



The vertex of parabola y = 2 (X-2) square-7 is C, and the image of function y = - kx-3 passes through C, then k =?


The vertex is (2, - 7)
-7=-2k-3
k=2