已知等腰梯形OABC的頂點(diǎn)A,B在復(fù)平面上對(duì)應(yīng)的復(fù)數(shù)分別為1+2i、-2+6i,且O是坐標(biāo)原點(diǎn),OA∥BC.求頂點(diǎn)C所對(duì)應(yīng)的復(fù)數(shù)z.
由題意可得O(0,0),A(1,2),B(-2,6),設(shè)C(x,y)
由等腰梯形可得|OC|=|AB|且OA∥BC,
∴
| x2+y2=(?2?1)2+(6?2)2 | y?6=2(x+2) |
| |
,
解得
,或
(舍去)
∴頂點(diǎn)C所對(duì)應(yīng)的復(fù)數(shù)z=-5