Welcome :: Homework Help and Answers :: Mathskey.com
Welcome to Mathskey.com Question & Answers Community. Ask any math/science homework question and receive answers from other members of the community.

13,435 questions

17,804 answers

1,438 comments

776,838 users

Find the center and the radius of the circle whose equation is given by x 2 + 4x + y 2 - 8y = 5.

0 votes
Center and radius
asked Oct 21, 2018 in ALGEBRA 2 by anonymous

1 Answer

0 votes

Given equation x^2 + 4x  + y^2 - 8y = 5

x^2 + 4x  + y^2 - 8y - 5  =  0

x^2+ y^2 + 4x  - 8y - 5  =  0

Compare it to circle equation x ^2 + y ^2 + 2gx + 2fy + c = 0.

c  =  - 5

2g  =  4

g  =  2

2f  =  - 8

f  =  - 4

Center =  ( -g , -f )

            =  ( -2 , 4 )

Radius  =  √(^2 + f ^2 - c)

             =  √(4 + 16 + 5)

             =  √25

Answer :

Radius of circle( )  =  5

Center =  ( -2 , 4 )

answered Oct 21, 2018 by homeworkhelp Mentor

Related questions

...