utefdxd的部落格

標題:

maths

發問:

Q1.(5+7i/2-4i)^2=? Q2.點樣將2m^2+3mn+n^2轉成(2m+n)(m+n)? 更新: 唔該列明步驟~

• 仙樂影音台劇DVD的價錢
• Sony Ericsson手機 邊個型號相機最高像素-
• 找英文報導311日本大地震地的文章

此文章來自奇摩知識+如有不便請留言告知

最佳解答:

1 [(5+7i)/(2-4i)]^2 =[(5+7i)/(2-4i)*(2+4i)/(2+4i)]^2 =[(10+20i+14i-28)/(4+16)]^2 =[(-18+24i)/20]^2 =(324-1224i-1156)/400 =(-832-1224i)/400 =(-104-153i)/50 2. 2m^2+3mn+n^2 =2m^2+3mn+n^2+2m^2-2m^2+mn-mn =4m^2+4mn+n^2-2m^2-mn =(2m+n)^2-m(2m+n) =(2m+n)[(2m+n)-m] =(2m+n)(m+n)

其他解答:

Q1.(5+7i/2-4i)^2=? =(5 + 7/2i - 8/2i)^2 =(5 - i/2)^2 =(5 - i/2) x (5 - i/2) =5 x (5 - i/2) - i/2 x (5 - i/2) =(25 - 5/2i) - (5/2i - 1/4(i^2)) =25 - 5/2i - 5/2i - (-1/4(i^2)) =25 - 5/2i - 5/2i +1/4(i^2) =25 - 10/2i +1/4(i^2) =25 - 5i +1/4(i^2) Q2.點樣將2m^2+3mn+n^2轉成(2m+n)(m+n)? 2m^2+3mn+n^2 =(2x1)(mxm)+3mn+(1xnxn) =(2m x1m )+3mn+(1n)(1n) =(2m + 1n)(1m + 1n) 即(2m + n)(m + n) 希望涂上顏色你會容易明白D 記得俾分我4E350C6F8B48ECA2