SOLUTION: what is the radius of the circle x^2+y^2-2x-4y-31=0.

Question 771465: what is the radius of the circle x^2+y^2-2x-4y-31=0.
Answer by Cromlix(4381) (Show Source): You can put this solution on YOUR website!
The general equation of a circle
= x^2 + y^2 + 2gx + 2fy + c = 0
Centre = (-g,-f)
Therefore the equation of the circle:
x^2 + y^2 - 2x - 4y - 31 = 0
has (1,2) as the coordinates of its centre.
The radius is found from the equation:
square root of(g^2 + f^2 - c)
square root of(1^2 + 2^2 -(-31))
square root of(1 + 4 + 31)
square root of (36)
= 6 units.
Hope this helps.
:-)
RELATED QUESTIONS
The radius of a circle defined by... (answered by solver91311)

The equation x^2+y^2-2x-4y-4=0 represents a circle. What are the coordinates for the... (answered by mathmate)

What is the radius of the circle... (answered by ewatrrr)

What is the center of the curve x^2+y^2-2x-4y-31=0.Please... (answered by MathLover1)

find the center and radius of the circle having equation... (answered by Edwin McCravy)

how do you find the radius of the circle... (answered by solver91311)

Find the center and radius of a circle given:... (answered by josgarithmetic)

please solve this problem: For what value of k will the equation below describe a... (answered by Fombitz)

Find the center and radius of the circle... (answered by solver91311)