gwd 23

sophialj

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.

答案d,没想通B怎么得的,我选的a。谢谢各位了，数学比较小白，别忽视我

qiuhailing01

MM,你能选A说明你知道如何运用半径长度计算R平方+S平方的了,是吧?

条件2说(√2, -√2)在圆上,正好给你一个条件计算出半径: 该圆的半径=(√2)平方 +(√2)平方开根 = 2.