1. 1 + rs
2. 2 + rs
3. 1 - rs
答案係1,我想問Y?謝謝
更新1:
答案係1,我想問why?謝謝
一條f.2 maths題 10分 急
2011-10-23 7:52 pm
Which of the following is/are factor(s) of 1 + rs(rs+2)?
1. 1 + rs
2. 2 + rs
3. 1 - rs
答案係1,我想問Y?謝謝
1. 1 + rs
2. 2 + rs
3. 1 - rs
答案係1,我想問Y?謝謝
回答 (2)
2011-10-23 8:15 pm
✔ 最佳答案
Let x = rs 1 + rs(rs + 2)
= 1 + x(x + 2)
= x^2 + 2x + 1
=(x + 1)^2
= (rs + 1)^2
And so the answer should be 1 only
2011-10-23 9:34 pm
1+rs(rs+2)= 1+r^2s^2+2rs= r^2s^2+2rs+1=(rs+1)^2
because of the identity: a^2+2ab+b^2=(a+b)^2
** ^2 = 二次方
2011-10-23 13:34:44 補充：
so the answer is 1 :) and 1 only
2011-10-23 13:34:57 補充：
hope it helps :D
because of the identity: a^2+2ab+b^2=(a+b)^2
** ^2 = 二次方
2011-10-23 13:34:44 補充：
so the answer is 1 :) and 1 only
2011-10-23 13:34:57 補充：
hope it helps :D
參考: me
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