【導(dǎo)讀】[解析]∵2i-5的虛部是2,5i+2i2的實(shí)部是-2,∴選A.7.如果x-1+yi與i-3x是共軛復(fù)數(shù),則實(shí)數(shù)x=_____,y=________.8.i為虛數(shù)單位,設(shè)復(fù)數(shù)z1、z2在復(fù)平面內(nèi)對(duì)應(yīng)的點(diǎn)關(guān)于原點(diǎn)對(duì)稱,若z1. =2-3i,則z2=______________.∴當(dāng)m=3時(shí),原不等式成立.是±i,排除D,故選A.[解析]由題意知a2-2a=0且a2-a-2≠0,4.若z1=(x-2)+yi與z2=3x+i互為共軛復(fù)數(shù),則z1對(duì)應(yīng)的點(diǎn)在第幾象限(). 5.設(shè)(1+i)sinθ-對(duì)應(yīng)的點(diǎn)在直線x+y+1=0上,則tanθ的值為________.。6.若復(fù)數(shù)z滿足z=|z|-3-4i,則z=________.[解析]∵z=+i,即實(shí)數(shù)m的取值范圍是-1+52<m<32.[解析]設(shè)x=x0是方程的實(shí)根,代入方程并整理得+i=0.∴方程的實(shí)根為x=2或x=-2,相應(yīng)的k的值為k=-22或k=22.