Form 5 数学题不会做~~！厉害的拜托进来帮我

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laikokseng

2012-10-31 11:22 PM

remember (add sugar to coffee )

QKeitaroQ

2012-11-1 05:26 AM

回复 QKeitaroQ
那我在这祝你考到A+咯
别叫我名发表于 2012-10-31 10:46 PM

赫赫~谢谢~有问题的话我会再来打扰你

QKeitaroQ

2012-11-1 05:28 AM

remember (add sugar to coffee )
laikokseng 发表于 2012-10-31 11:22 PM

i understand already~ thank you =D
不过这里不写华语会扣分哦~

warriorwj

2012-11-1 09:07 AM

回复 warriorwj

为什么 TAN要-1呢？
dream-dream 发表于 2012-10-31 07:59 PM

其实不算 tan -1 这是代表 arctangent 的意思。。。
如果你是用 350/570 就是按 shift 然后按 tan。。。

QKeitaroQ

2012-11-1 01:52 PM

回复 QKeitaroQ
那我在这祝你考到A+咯
别叫我名发表于 2012-10-31 10:46 PM

呃，这个会吗？？
There are 8 white and 12 brown envelopes in a drawer. Ali put another y white envelopes into the drawer. One envelope is drawn at random from the drawer. If the probabiltity of drawing a white envelope is 3 over 5, find the value of y.~

P2PSYSTEM

2012-11-1 02:10 PM

回复 55# QKeitaroQ

There are 8 white and 12 brown envelopes in a drawer. Ali put another y white envelopes into the drawer. One envelope is drawn at random from the drawer. If the probabiltity of drawing a white envelope is 3 over 5, find the value of y.~

(8+y)/(8+12+y)=3/5
8+y=12+3/5y
2/5y=4
4/(2/5)=y
y=10