y=ax²+bx+c
=a(x^2+b/2a)^2-b^2/4a+c.
=a(x+b/2a)-(b^2+4ac)/4a.
其顶点坐标为:((-b/2a,-(b^2+4ac/4a)).
y=-2x^2+5x+3.
a=2,b=5,c=3
-b/2a=5/4,-(b^2+4ac/4a)=49/8
函数 y=-2x²+5x+3顶点坐标为:(5/4,49/8).
y=ax²+bx+c
=a(x^2+b/2a)^2-b^2/4a+c.
=a(x+b/2a)-(b^2+4ac)/4a.
其顶点坐标为:((-b/2a,-(b^2+4ac/4a)).
y=-2x^2+5x+3.
a=2,b=5,c=3
-b/2a=5/4,-(b^2+4ac/4a)=49/8
函数 y=-2x²+5x+3顶点坐标为:(5/4,49/8).