Discover the best answers at Westonci.ca, where experts share their insights and knowledge with you. Explore a wealth of knowledge from professionals across different disciplines on our comprehensive platform. Experience the convenience of finding accurate answers to your questions from knowledgeable experts on our platform.

What are the center and radius of the circle defined by the equation
x2 + y2 - 6x+8y +21 = 0 ?
-
O A. Center (3,-4); radius 2
O B. Center (-3, 4); radius 2
O C. Center (3, -4); radius 4
O
D. Center (-3, 4); radius 4


Sagot :

A


Step by step explanation This is how I got the answer to your question and I gave you the solution I hope this helps you out

Answer:

Radus: 2, Center (3,-4)

Step-by-step explanation:

You first move the constant to the right then reorder the terms: x^2+y^2-6x+8y=-21.

You then complete the square: x^-6x+9+y^2=-21+9

Then factor: (x-3)^2+y^2+8y=-12

Then complete the square for the other term:

(x-3)^2+y^2+8y+12=-12+16

Then factor: (x-3)^2+(y+4)^2=4

4 is the radius squared, so the radius must be 2.

The center is the opposite of the constant in the parenthesis so the center must be (3,-4)