Connect with a community of experts and enthusiasts on IDNLearn.com. Our platform provides detailed and accurate responses from experts, helping you navigate any topic with confidence.

Select the correct answer from each drop-down menu.

The general form of the equation of a circle is [tex]7x^2 + 7y^2 - 28x + 42y - 35 = 0[/tex].

The equation of this circle in standard form is [tex]\square[/tex].

The center of the circle is at the point [tex]\square[/tex], and its radius is [tex]\square[/tex] units.


Sagot :

To convert the given general form of the equation of a circle [tex]\(7x^2 + 7y^2 - 28x + 42y - 35 = 0\)[/tex] to its standard form, we need to follow a few steps:

1. Simplify the equation:
First, divide the entire equation by 7 to make the coefficients of [tex]\(x^2\)[/tex] and [tex]\(y^2\)[/tex] equal to 1:
[tex]\[ x^2 + y^2 - 4x + 6y - 5 = 0 \][/tex]

2. Rearrange and group terms:
Rearrange and group the [tex]\(x\)[/tex] terms together and the [tex]\(y\)[/tex] terms together:
[tex]\[ (x^2 - 4x) + (y^2 + 6y) = 5 \][/tex]

3. Complete the square:
We complete the square separately for the [tex]\(x\)[/tex] terms and the [tex]\(y\)[/tex] terms.

For [tex]\(x\)[/tex]-terms:
[tex]\[ x^2 - 4x \quad \Rightarrow \quad (x - 2)^2 - 4 \][/tex]

For [tex]\(y\)[/tex]-terms:
[tex]\[ y^2 + 6y \quad \Rightarrow \quad (y + 3)^2 - 9 \][/tex]

4. Substitute back into the equation:
Substitute these completed squares back into the rearranged equation:
[tex]\[ (x - 2)^2 - 4 + (y + 3)^2 - 9 = 5 \][/tex]

5. Simplify:
Combine like terms and simplify:
[tex]\[ (x - 2)^2 + (y + 3)^2 - 13 = 5 \quad \Rightarrow \quad (x - 2)^2 + (y + 3)^2 = 18 \][/tex]

Thus, the equation of the circle in standard form is:
[tex]\[ (x - 2)^2 + (y + 3)^2 = 18 \][/tex]

6. Identify the center and radius:
The standard form of a circle's equation is [tex]\((x - h)^2 + (y - k)^2 = r^2\)[/tex], where [tex]\((h, k)\)[/tex] is the center and [tex]\(r\)[/tex] is the radius.
From the equation [tex]\((x - 2)^2 + (y + 3)^2 = 18\)[/tex], we can see that the center of the circle is:
[tex]\[ (h, k) = (2, -3) \][/tex]
And the radius [tex]\(r\)[/tex] is the square root of 18:
[tex]\[ r = \sqrt{18} \approx 4.242640687119285 \][/tex]

Therefore:
- The standard form of the equation of this circle is [tex]\((x - 2)^2 + (y + 3)^2 = 18\)[/tex].
- The center of the circle is at the point [tex]\((2, -3)\)[/tex].
- The radius of the circle is approximately [tex]\(4.242640687119285\)[/tex] units.

So the correct answers are:
- The equation of this circle in standard form is [tex]\((x - 2)^2 + (y + 3)^2 = 18\)[/tex].
- The center of the circle is at the point [tex]\((2, -3)\)[/tex].
- Its radius is approximately [tex]\(4.242640687119285\)[/tex] units.
We appreciate every question and answer you provide. Keep engaging and finding the best solutions. This community is the perfect place to learn and grow together. Thank you for visiting IDNLearn.com. We’re here to provide accurate and reliable answers, so visit us again soon.