Urgent !Quatratic equation 30pts
2008-11-02 7:28 pm
The figure shows a toy.A soldier is hung from a parachute which is in the form of an open hemisphere with radius r cm.The soldier is 14 cm below the top of the parachute and the strings are each 10 cm long .Find the 2 possible values of r.
回答 (1)
2008-11-02 7:54 pm
✔ 最佳答案
By Pythagoras theorem, (14-r)^2 + r^2 = 10^2
196 + r^2 - 28r + r^2 - 100 = 0
2r^2 - 28r + 96 = 0
r^2 - 14r + 48 = 0
(r-6)(r-8) = 0
So r = 6 or 8 cm.
收錄日期: 2021-04-25 22:38:07
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20081102000051KK00591