For each of the the following quaratic equations,
find
(a)the optimum value,
(b)(i)the direction of opening
(ii)the vertex,
(iii)the axis of symmetry
of its graph by completing square
1. y=2(2x-x)(x+2)-4x
2.y=(x+1)^2+(2(x-1)
3.In the figure,the base and the height of a parallelogram are (6-x)cm and 2x cm respectively.
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(a)Find the maximum area of this parallelogram.
(b)Find the height and the base of the parallelogram when the area is maximum.
唔該幫下手
For each of the the following quaratic equations,
find
(a)the optimum value,
(b)(i)the direction of opening
(ii)the vertex,
(iii)the axis of symmetry
of its graph by completing square
1. y=2(2x-x)(x+2)-4x
2.y=(x+1)^2+(2(x-1)
1)y=2(x)(x+2)-4x
y=2x^2
a)(0,0)
b)i)upward
ii)(0,0)
iii)x=0
2)y=(x^2+2x+1)+2x-2
y=x^2+4x-1
y=(x+2)^2-5
a)(-2,-5)
b)i)upward
ii)(-2,-5)
iii)x=-2
3.In the figure,the base and the height of a parallelogram are (6-x)cm and 2x cm respectively.
(a)Find the maximum area of this parallelogram.
(b)Find the height and the base of the parallelogram when the area is maximum.
3a)let A=area parallelogram
A=(6-x)(2x)=12x-2x^2=-2(x^2-6x)=-2(x-3)^2+18
the maximun area of it is 18cm^2
b)the height=2(3)=6cm
the base=(6-3))=3cm
