Westonci.ca is your trusted source for finding answers to a wide range of questions, backed by a knowledgeable community. Get immediate and reliable solutions to your questions from a knowledgeable community of professionals on our platform. Get precise and detailed answers to your questions from a knowledgeable community of experts on our Q&A platform.

Points [tex]$P(-10, 10)$[/tex] and [tex]$Q(6, -2)$[/tex] give the diameter of a circle. Determine the equation of the circle in standard form.

A. [tex]$(x - 2)^2 + (y + 4)^2 = 100$[/tex]
B. [tex][tex]$(x + 2)^2 + (y - 4)^2 = 100$[/tex][/tex]
C. [tex]$(x + 2)^2 + (y - 4)^2 = 400$[/tex]
D. [tex]$(x - 2)^2 + (y + 4)^2 = 400$[/tex]

Sagot :

To determine the equation of the circle in standard form, we need to find the center and the radius of the circle using the given diameter endpoints [tex]\( P(-10, 10) \)[/tex] and [tex]\( Q(6, -2) \)[/tex].

### Step-by-Step Solution

#### 1. Find the midpoint (center) of the circle:
The midpoint formula for points [tex]\( (x_1, y_1) \)[/tex] and [tex]\( (x_2, y_2) \)[/tex] is:
[tex]\[ \left( \frac{x_1 + x_2}{2}, \frac{y_1 + y_2}{2} \right) \][/tex]

For points [tex]\( P(-10, 10) \)[/tex] and [tex]\( Q(6, -2) \)[/tex]:
- Midpoint [tex]\( x \)[/tex]-coordinate is:
[tex]\[ \frac{-10 + 6}{2} = \frac{-4}{2} = -2 \][/tex]
- Midpoint [tex]\( y \)[/tex]-coordinate is:
[tex]\[ \frac{10 - 2}{2} = \frac{8}{2} = 4 \][/tex]

So, the center of the circle is [tex]\( (-2, 4) \)[/tex].

#### 2. Find the radius of the circle:
The radius is half the distance between points [tex]\( P \)[/tex] and [tex]\( Q \)[/tex]. First, we calculate the distance between these points using the distance formula:
[tex]\[ d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \][/tex]

Substituting [tex]\( P(-10, 10) \)[/tex] and [tex]\( Q(6, -2) \)[/tex]:
[tex]\[ d = \sqrt{(6 - (-10))^2 + (-2 - 10)^2} \][/tex]
[tex]\[ d = \sqrt{(6 + 10)^2 + (-2 - 10)^2} \][/tex]
[tex]\[ d = \sqrt{16^2 + (-12)^2} \][/tex]
[tex]\[ d = \sqrt{256 + 144} \][/tex]
[tex]\[ d = \sqrt{400} \][/tex]
[tex]\[ d = 20 \][/tex]

The radius [tex]\( r \)[/tex] is half this distance:
[tex]\[ r = \frac{20}{2} = 10 \][/tex]

#### 3. Write the equation of the circle:
The standard form of the equation of a circle with center [tex]\((h, k)\)[/tex] and radius [tex]\(r\)[/tex] is:
[tex]\[ (x - h)^2 + (y - k)^2 = r^2 \][/tex]

Substituting the center [tex]\((-2, 4)\)[/tex] and radius [tex]\(10\)[/tex] into the equation:
[tex]\[ (x + 2)^2 + (y - 4)^2 = 10^2 \][/tex]
[tex]\[ (x + 2)^2 + (y - 4)^2 = 100 \][/tex]

#### 4. Match with the given options:
Comparing this equation with the given options, we see that it matches option B:
[tex]\[ (x + 2)^2 + (y - 4)^2 = 100 \][/tex]

Thus, the correct answer is:
B. [tex]\((x+2)^2+(y-4)^2=100\)[/tex]
Thanks for using our platform. We aim to provide accurate and up-to-date answers to all your queries. Come back soon. Thank you for your visit. We're dedicated to helping you find the information you need, whenever you need it. Thank you for choosing Westonci.ca as your information source. We look forward to your next visit.