數學移項一問題..~~

👨🏻‍🏫 學術台數學

云云云mi

2012-04-15 4:29 pm

求b

a+bi / a-bi =i

b [( a+i) / (a-i ) ] =i

b= 1

找錯處

回答 (3)

myisland8132

2012-04-15 7:32 pm

✔ 最佳答案

(a + bi)/(a - bi) = i

a + bi = ai + b

(a - b) = (a - b)i

So, a = b

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雪兒

2012-04-15 6:06 pm

a+bi / a-bi =i
a+bi=i(a-bi)
a+bi=ai-bi^2
bi+bi^2=ai-a
b(i+i^2)=ai-a
b=(ai-a)/(i+i^2)

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tttfffkkk

2012-04-15 5:35 pm

(a+bi)/(a-bi)
=[b(a/b+i)/b(a/b-i)]
=(a/b+i)/(a/b-i)
≠b[(a+i)/(a-i)]
[(a+i)/(a-i)]
=(a+i)²/(a-1)(a+1)
=(a²+2ai-1)/(a²-1)
≠i

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