Question

Identify the center and radius for the following equation: x²+y²-6x+10y-15=0

Answer 1

the general form an equation of circle is :
x^2 + y^2 + Ax + By + C = 0, with A, B, and C are the constants
so to get the center of circle and its radius, u can use the formula :
the center is (-A/2 , -B/2)
r = sqrt(A^2/4 + B^2/4 - C)

Answer 2

thank you!! is that the final answer?

Answer 3

that is the formula only...
so, if given the equation : x²+y²-6x+10y-15=0, it means A=-6, B=10, C=-15
now, apply that numbers to formula above ^, what u get

Answer 4

got it ?

Answer 5

thanks!! @RadEn so what would the center and radius be from that?

Answer 6

let the coordinat of center is (h, k)
with, h=-A/2 = -(-6)/2 = 6/2 = ....
k = -B/2 = -10/2 = ......
so, the coordinat center is (... , ...)
r = sqrt (A^2/4 + B^2/4 - C)
r = sqrt[ (-6)^2/4 + (10)^2/4 - (-15)]
r = sqrt(36/4 + 100/4 + 15)
r = sqrt(9 + 25 + 15)
r = sqrt(49) = ....

Answer 7

so r=7 and center= (3,-5)??
thank u so much :) @raden

Answer 8

yeah, that's right
welcome :*