GWD1-23,坐标(发现这一题链接里没有哦)

追梦爱我

请教如何解题

Q23:

In the xy-plane, point (r, s) lies on a circle with center at the origin.  What is the value of r² + s²?

(1)     The circle has radius 2.

(2)     The point (√2, -√2) lies on the circle.

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

[此贴子已经被作者于2008-12-3 23:36:40编辑过]

zhhyyy

两个条件其实性质一样，一个告诉半径，即直角三角形的斜边，而斜边平方就等于所求

另一个告诉园上一个点可求斜边，即半径，与1同理