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用“描点法”画二次函数y=ax2+bx+c的图象时.列了如下表格: x … -2...
用“描点法”画二次函数y=ax
2+bx+c的图象时.列了如下表格:
x | … | -2 | -1 | 0 | 1 | 2 | … |
y | … | -6![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021230646687724632/SYS201310212306466877246007_ST/0.png) | -4 | -2![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021230646687724632/SYS201310212306466877246007_ST/1.png) | -2 | -2![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131021230646687724632/SYS201310212306466877246007_ST/2.png) | … |
根据表格上的信息同答问题:该二次函数y=ax
2+bx+c在x=3时,y=( )
A.-2
B.-4
C.-6.5
D.-2.5
考点分析:
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