Question

一個(gè)動(dòng)點(diǎn)在圓x²+y²=1上移動(dòng)時(shí)，它與定點(diǎn)(3，0)連線中點(diǎn)的軌跡方程是

A.(x+3)²+y²=4                                                        B.(x－3)²+y²=1

C.(2x－3)²+4y²=1                                            D.(x+)²+y²=

Answer 1

C

解析:

令圓上動(dòng)點(diǎn)為(x₀,y₀)，它與定點(diǎn)(3，0)連線的中點(diǎn)為(x,y)，則有

(2x－3)²+(2y)²=1(2x－3)²+4y²=1.