The general form of the equation of a circle is x2 + y2 + 42x + 38y − 47 = 0. The equation of this circle in standard form is .

The center of the circle is at the point , and its radius is units.

The general form of the equation of a circle that has the same radius as the above circle is .

The general form of the equation of a circle is x2 y2 42x 38y 47 0 The equation of this circle in standard form is The center of the circle is at the point and class=

Respuesta :

Answer:

(-21,-19)

[tex]\sqrt{849}[/tex]

Standard form

Step-by-step explanation:

We are given the equation of circle

[tex]x^2+y^2+42x+38y-47=0[/tex]

General equation of circle:

[tex]x^2+y^2+2gx+2fy+c=0[/tex]

Centre: (-g,-f)

Radius: [tex]\sqrt{g^2+f^2-c}[/tex]

Compare the equation to find f, g and c from the equation

[tex]g\rightarrow 21[/tex]

[tex]f\rightarrow 19[/tex]

[tex]c\rightarrow -47[/tex]

Centre: (-21,-19)

Radius (r) [tex]=\sqrt{21^2+19^2+47}=\sqrt{849}[/tex]

Standard form of circle:

[tex](x+21)^2+(y+19)^2=849[/tex]

The centre of circle at the point (-21,-19) and its radius is [tex]\sqrt{849}[/tex].

The general form of the equation of a circle that has the same radius as the above circle is standard form.

Answer: The center of the circle is at the point (-21,-19), and its radius is  [tex]\sqrt{849}[/tex] units.

The standard form of circle: [tex](x+21)^2+(y+19)^2=849[/tex]

Step-by-step explanation:

The given the equation of circle :-

[tex]x^2 + y^2 + 42x + 38y- 47 = 0[/tex]

The general equation of circle is given by :

[tex]x^2+y^2+2hx+2gy+a=0[/tex]

Here, the center of circle= (-h,-g)

and radius =[tex]\sqrt{h^2+g^2-a}[/tex]

Now, Comparing the given equation to the general equation, we get  

[tex]2h=42\\\Rightarrow\ h=21\\\\2g=38\\\Rightarrow\ g=19[/tex]

Thus, the center of the given circle= (-21,-19)

Radius of given circle = [tex]\sqrt{21^2+19^2+47}=\sqrt{849}[/tex]

Now, the standard form of circle will be

[tex](x-(-21))^2+(y-(-19))^2=(\sqrt{849})^2\\\\\Rightarrow\ (x+21)^2+(y+19)^2=849[/tex]