设z是虚数,w=z 1 z是实数,且w 大于-1,小于2,求

i^3=-i;z=(1-a^2i)/(-i);上下同乘i,则z=i+　a＾2,因为是纯虚数,所以a＾2＝0,则a＝0

1.Z=a+bi1/z=a/(a^2+b^2)-b/(a^2+b^2)iZ+Z分之一是实数,b-b/(a^2=b^2)=0a^2+b^2=1|Z|=√(a^2+b^2)=1-1

设z=a+bi(3＋4i)z=(3X-4Y)+(4X+3Y)iZ是纯虚数,3X-4Y=0｜z｜＝1X=4/5Y=3/5或X=-4/5Y=-3/5Z上面一横=4/5-3/5i或-4/5+3/5i

设z=a+biz+i=a+(b+1)i是实数,则b=-1所以z=a-iz/(1-i)=(a-i)(1+i)/(1-i)(1+i)=(a+ai-i-i^2)/(1-i^2)=(a+1+(a-1)i)/2

设z=a+bi;w=z+i=a+(b+1)i;z-2=(a-2)+bi;z+2=(a+2)+bi;(z-2)/(z+2)=[(a-2)(a+2)+b^2]/2b^2+[b(a+2)-(a-2)b]/2

设z=x+yi(x、y属于R)PS:这句话一定要写,以后高考要按此来给分!z^2+2z=x^2-y^2+2xyi+2x+2yi=(x^2-y^2+2x)+(2xy+2y)iPS:实部归实部,虚部归虚部

z=a+bi1/z=(a-bi)/(a+bi)(a-bi)=(a-bi)/(a²+b²)则a+a/(a²+b²)+[b-b/(a²+b²)]

(3+4i)*(3-4i)i=25i(3-4i)i=3i+4|(3i+4)/5|=1z=(3i+4)/5

楼上强人z+1/z=a+ib+1/(a+ib)=a+ib+(a-ib)/(a^2+b^2)=>[a+a/(a^2+b^2)]+i[b-b/(a^2+b^2)]是实数=>[b-b/(a^2+b^2)]=

前者z是实数1,后者z是实数.所以z是实数.再问：能不能再帮忙做个？？http://zhidao.baidu.com/question/368008444324911244.html谢谢再问：能不能再

1、设z=x+yi(x、y∈R,y≠0),w=x+yi+1/(x+yi)=x+x/(x²+y²)+[y-y/(x²+y²)]i由w是实数,得y-y/(x&sup

设Z=r(cosθ+isinθ),则1/Z=1/r*(cosθ-isinθ)所以Z+1/Z=(r+1/r)cosθ+(r-1/r)isinθ由于Z+1/Z是实数,所以r-1/r=0所以r=1从而|Z|

1/2+(1/2)i

Z+Z^2=1+i+(1+i)^2=1+i+1+2i+(i)^2=2+i+2i-1=1+3i

Z=4/5+3/5i或Z=-4/5-3/5i

z=2(1-i)/(1+i)(1-i)+ai=2(1-i)/(1+1)+ai=1-i+ai=1+(a-1)i所以a-1=0a=1

设z=a+bi(ab属于Rb不等于0）所以z+1/z=a+bi+(a-bi)/(a^2+b^2)为实数[所以b-b/(a^2+b^2)=0因为b不等于0所以a^2+b^2=1z的膜为1]所以a+a/(

设3z=a＋bi,则w=[(a＋2)＋bi]/[(a－2)＋bi]=[(a＋2)＋bi][(a－2)－bi]/[(a－2)²＋b²],其实部为0且虚部不为0,则(a＋2)(a－2)

(1)令z=a+bi,有w=z+1/z=a+bi+1/(a+bi)=(a^2+2abi-b^2+1)/(a+bi)=(a^2-b^2+1+2abi)/(a+bi)即a^2-b^2+1+2abi=w(a

z+1\z为实数z+1/z=z'+1/z'zzz'+z'=zz'z'+z(z-z')(zz'-1)=0而z是虚数,z≠z',因此(z-z')(zz'-1)=0zz'=1|z|=1其中z'表示z的共轭