根号下[x^2+(y+4)^2] + 根号下[x^2+(y-4)^2] = 12
问题描述：
根号下[x^2+(y+4)^2] + 根号下[x^2+(y-4)^2] = 12
答
根号下[x^2+(y+4)^2] + 根号下[x^2+(y-4)^2]= 12√[x^2+(y+4)^2] + √[x^2+(y-4)^2]= 12[x^2+(y+4)^2] + 2√[x^2+(y+4)^2][x^2+(y-4)^2] +[x^2+(y-4)^2]= 144x^2+y^2+8y+16 + 2√[x^2+(y+4)^2][x^...