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标题: prep-ds-2-43 [打印本页]

作者: dimder    时间: 2009-8-29 19:47     标题: prep-ds-2-43

prep-ds-2-43

 

 

Circle C and line k lie in the xy-plane. If circle C is centered at the origin and has radius 1, does line k intersect circle C ?

(1) The x-intercept of line k is greater than 1.

(2) The slope of line k is -1/10

答案是E

我的问题是:条件(1)理解为 line K 在X轴上的截距的绝对值是1, 因为截距可正可负的. 对吗?


作者: liudi    时间: 2009-8-30 08:41

截距是线段,只能是非负数, 而坐标可正可负;

而具体于坐标轴上截距可能在负方向上,此时坐标为负数,截距在正方向上,坐标为正数.


作者: lanshichao90    时间: 2009-9-2 06:36

well, in college algebra, intercept could be negative.




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