When k does not exist, the equation is x= 1, which is inconsistent with the meaning of the question.

When k exists: Let the equation (

Point-oblique type

)y=kx- 1-k

Simultaneous y=kx- 1-k and elliptic equations,

street

Get:

x 1+x2=(8k^2+8k)/(4k^2+ 1)

From the midpoint formula: (x 1+x2)/2= 1.

The solution is k= 1/4.

So the equation is: 4y-x+5=0.

You can check it! Combined with elliptic equation, answer at two points to see if A is the midpoint! You're upstairs

miscount

Yes!