配套习题- 用待定系数法求二次函数解析式 -【青果学院】

1/5单选题

难度：

1.已知二次函数的图象经过点（-1，-5），（0，-4）和（1，1），则这二次函数的表达式为（　　）

A	y=-6x²+3x+4
B	y=-2x²+3x-4
C	y=x²+2x-4
D	y=2x²+3x-4

正确答案：RA==

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

2/5单选题

难度：

2.顶点为（6，0），开口向下，开口的大小与函数y=

x²的图象相同的抛物线所对应的函数是（　　）

A
B
C
D

正确答案：RA==

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

3/5单选题

难度：

3.一个二次函数的图象的顶点坐标是（2，4），且过另一点（0，-4），则这个二次函数的解析式为（　　）

A	y=-2（x+2）²+4
B	y=-2（x-2）²+4
C	y=2（x+2）²-4
D	y=2（x-2）²-4

正确答案：Qg==

6Kej77ya4oi15LqM5qyh5Ye95pWw55qE5Zu+6LGh55qE6aG254K55Z2Q5qCH5piv77yIMu+8jDTvvInvvIw8YnI+4oi06K6+6L+Z5Liq5LqM5qyh5Ye95pWw55qE6Kej5p6Q5byP5Li6eT1h77yIeC0y77yJPHN1cD4yPC9zdXA+KzTvvIw8YnI+5oqK77yIMO+8jC3vvIw077yJ5Luj5YWl5b6XYT0tMu+8jDxicj7iiLTov5nkuKrkuozmrKHlh73mlbDnmoTop6PmnpDlvI/kuLp5PS0y77yIeC0y77yJPHN1cD4yPC9zdXA+KzTvvI48YnI+5pWF6YCJQu+8jg==

4/5单选题

难度：

4.将二次函数y=x²-2x+3化为y=（x-h）²+k的形式，结果为（　　）

A	y=（x+1）²+4
B	y=（x+1）²+2
C	y=（x-1）²+4
D	y=（x-1）²+2

正确答案：RA==

6Kej77yaeT14PHN1cD4yPC9zdXA+LTJ4KzPvvIw8YnI+Pe+8iHg8c3VwPjI8L3N1cD4tMngrMe+8iSsy77yMPGJyPj3vvIh4LTHvvIk8c3VwPjI8L3N1cD4rMu+8jjxicj7mlYXpgInvvJpE77yO

5/5单选题

难度：

5.若所求的二次函数图象与抛物线y=2x²-4x-1有相同的顶点，并且在对称轴的左侧，y随x的增大而增大，在对称轴的右侧，y随x的增大而减小，则所求二次函数的解析式为（　　）

A	y=-x²+2x+4
B	y=-ax²-2ax-3（a＞0）
C	y=-2x²-4x-5
D	y=ax²-2ax+a-3（a＜0）

正确答案：RA==

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