Select the correct answer.

Which equation represents a circle with a center at [tex]$(-5,5)$[/tex] and a radius of 3 units?

A. [tex]\((x+5)^2+(y-5)^2=9\)[/tex]

B. [tex]\((x-5)^2+(y+5)^2=9\)[/tex]

C. [tex]\((x+5)^2+(y-5)^2=3\)[/tex]

D. [tex]\((x-5)^2+(y+5)^2=3\)[/tex]

E. [tex]\((x+5)^2+(y-5)^2=6\)[/tex]



Answer :

To determine which equation represents a circle with a center at [tex]\((-5, 5)\)[/tex] and a radius of 3 units, we'll use the standard form of the equation of a circle. Here's a step-by-step explanation:

1. Standard Form of Circle Equation:
The general 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]

2. Identify Given Values:
- Center [tex]\((h, k) = (-5, 5)\)[/tex]
- Radius [tex]\(r = 3\)[/tex]

3. Substitute the Values:
Substitute [tex]\(h = -5\)[/tex], [tex]\(k = 5\)[/tex], and [tex]\(r = 3\)[/tex] into the standard equation:
[tex]\[ (x - (-5))^2 + (y - 5)^2 = 3^2 \][/tex]

4. Simplify the Equation:
Simplify the equation step-by-step:
[tex]\[ (x + 5)^2 + (y - 5)^2 = 9 \][/tex]

So, the correct equation representing the circle with center [tex]\((-5, 5)\)[/tex] and radius 3 is:
[tex]\[ (x + 5)^2 + (y - 5)^2 = 9 \][/tex]

Among the given choices, the equation that matches this form is:
A. [tex]\((x+5)^2 + (y-5)^2 = 9\)[/tex]

Therefore, the correct answer is [tex]\(\boxed{A}\)[/tex].