Question

. Determine a equação da circunferência de centro C( 13 ) e raio igual a 4:​

Answer 1

$C(x_C,y_C)=C(1,3)\\ r=4\ u.c.$

$\boxed{(x-x_C)^2+(y-y_C)^2=r^2}\ \therefore$

$(x-1)^2+(y-3)^2=4^2\ \therefore\ \boxed{(x-1)^2+(y-3)^2=16}\ \therefore$

$x^2-2x+1+y^2-6y+9=16\ \therefore$

$\boxed{x^2+y^2-2x-6y-6=0}$