GWD10-23

[iamdior]

D

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 (v2, -v2) lies on the circle. –v是根號

請問這題怎麼解呢?

[micht]

In the xy-plane, point (r s) lies on a circle with center at the origin, what is the value of [highlight=pink]r[sup]2[/sup]+s[sup]2[/sup][/highlight]?

(1) the circle has a radius 2;

(2) the point [highlight=pink](√2, -√2)[/highlight]lies on the circle


題目應該長這樣才對

[iamdior]

辛苦了..不好意思還麻煩您幫我更正
感謝~

[Martina]

雖然題目改過了 可是還是不太懂ㄝ

[homaru]

有一點(r,s)在一圓上, 圓心為原點(0,0), 問r[sup]2[/sup]+s[sup]2[/sup]
可知
r[sup]2[/sup]+s[sup]2[/sup]
=(r-0)[sup]2[/sup]+(s-0)[sup]2[/sup]
=半徑[sup]2[/sup]

條件1 半徑2, 充分
條件2 有另一點(√2, -√2)在圓上, 可知半徑, 充分