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what is are the coordinates of the center and length of the radius of the circle whose equation is x^2 + 6x + y^2 -4y =23

Respuesta :

arthurpdc
The general equation of a circle is: [tex](x-a)^2+(y-b)^2=r^2[/tex], where [tex](a,b)[/tex] is the center of the circle and [tex]r[/tex] is its radius. We'll put the equation of the statement in the general form:

[tex]x^2+6x+y^2-4y=23\\\\ x^2+6x+\underline{9}+y^2-4y+\underline{4}=23+\underline{9}+\underline{4}\\\\ (x+3)^2+(y-2)^2=36\\\\ (x+3)^2+(y-2)^2=6^2[/tex]

Then, by comparing the general equation of the circle and the equation above, we have:

[tex]\boxed{\text{Center:}~(-3,2)}\\\\ \boxed{\text{Radius:}~r=6~u.c.}[/tex]

Answer:

The coordinates (x,y) are -3,2 while the radius is 6cm

Step-by-step explanation:

The general form of the equation of a circle may be given as

(x - a)² + (y - b)² = c²

where c is the radius, a and b are the coordinates of the center of the circle along the x and y axis.

Given the circle

x^2 + 6x + y^2 - 4y =23

To make it similar to the general form

x^2 + 6x +9 + y^2 -4y + 4 =23 + 9 + 4

Factorizing

(x + 3)² + (y - 2)² = 36

Comparing with the general form,

c² = 36

c = √36

= 6 cm ( this is the radius)

a = -3, b = 2

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