(很笨的)GWD-1-Q23 請教圓形的解題思路

h5641 · 发表于 2009-4-20 20:42:00

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.

Answer:

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想請教這個跟圓形有關的解題思路

自己數學不好請原諒我但請幫助我

謝謝

zzhGGforever · 发表于 2009-4-20 20:53:00

2个条件都是能推出圆半径大小，任何一个以原点为圆心的圆，其上面任何一点到圆心距离等于半径，用坐标系距离公式或者向X,Y轴分别画垂线和原点构成直角三角（用勾股定理）得出x^2+y^2=R^2

h5641 · 发表于 2009-4-20 21:10:00

阿 ~ 我真的懂了!

謝謝 zzhGGforever ~

zzhGGforever · 发表于 2009-4-20 21:15:00

不谢不谢，楼主加油哈

所属分类: GMAT考试