(1)y=-x²+2x-3=-(x²-2x)-3=-(x²-2x+1)+1-3=-(x-1)²-2 (1,-3) 直线x=1
(2)y=-3x²+3=-3(x²-1)=-3(x-1)(x+1) x>=0 [0,+∞) 0 大 3
(3)增大 (1,+∞) 1 小 2
(4)x=(-2+4)/2=1
(5)y=a(x1-1)(x2-1) 4=a(1+3)(1-5) a=-1/4 y=-(x+3)(x-5)/4
(6)(0,9) (3,0)和(-3,0)
如果有误,请指正!
谢谢!
(1)y=-x²+2x-3=-(x²-2x)-3=-(x²-2x+1)+1-3=-(x-1)²-2 (1,-3) 直线x=1
(2)y=-3x²+3=-3(x²-1)=-3(x-1)(x+1) x>=0 [0,+∞) 0 大 3
(3)增大 (1,+∞) 1 小 2
(4)x=(-2+4)/2=1
(5)y=a(x1-1)(x2-1) 4=a(1+3)(1-5) a=-1/4 y=-(x+3)(x-5)/4
(6)(0,9) (3,0)和(-3,0)
如果有误,请指正!
谢谢!