椭圆x^2/25 + y^2/16 =1
c^2=25-16=9.|c|=3
椭圆的两个焦点(-3,0)(3,0)
△ABC的重心G(x,y)
点A在椭圆上运动A(x1,y1)
x=(-3+3+x1)/3
x1=3x
y=(0+0+y1)/3
y1=3y
(3x)^2/25+(3y)^2/16=1
9x^2/25+9y^2/16=1
椭圆x^2/25 + y^2/16 =1
c^2=25-16=9.|c|=3
椭圆的两个焦点(-3,0)(3,0)
△ABC的重心G(x,y)
点A在椭圆上运动A(x1,y1)
x=(-3+3+x1)/3
x1=3x
y=(0+0+y1)/3
y1=3y
(3x)^2/25+(3y)^2/16=1
9x^2/25+9y^2/16=1