貨運百科

標題:

(maths) polar form

發問:

If Z-4j / Z+ 3 is purely real, the locus of the point which represents Z in the Argand diagram is a straight line. 唔識做...help!~

最佳解答:

z-4j/z+3 let z=x+yj Then z-4j =x+yj-4j =x+(y-4)j and z+3 =x+yj+3 =(x+3)+yj so z-4j/z+3 =x+(y-4)j/(x+3)+yj =[x+(y-4)j]/[(x+3)+yj] *[(x+3)-yj]/[(x+3)-yj] =[x(x+3)+(y-4)y/(x+3)^2+y^2] + {[(x+3)(y-4)-xy]/[(x+3)^2+y^2]}j since z-4j/z+3 is a purely real (p.s:imaginary part =0) so[(x+3)(y-4)-xy]/[(x+3)^2+y^2]}=0 ---(x+3)(y-4)-xy=0 ---4x-3y+12=0(which is a straight line)

• 點令facebook update果陣sd e-mail比我@1@
• 點入影片and e-book入電話(k800i) - 10分
• a new-built house = a newly-built house 嗎？

此文章來自奇摩知識+如有不便請留言告知

其他解答: