Question

What is the radius of a circle defined by 2x^(2)+2y^(2)+4x-12y-30=0?

Answer 1

x^2 +2x + y^2 - 6y = 15

Answer 2

by diving by 3, and rearranging

Answer 3

x^2 +2x + 1 +y^2 -6y + 9 = 15 + 1 + 9

Answer 4

(x+1)^2 +(y-3)^2 = 25

therefore radius is sqrt25 = 5

Answer 5

mean by dividing by 2

Answer 6

Same type of question, just a bit more complex:
Find the axes and the centre of this curve:
9x^2-4xy+6y^2=10

Answer 7

do you know how to do this?

Answer 8

ahh no

Answer 9

i know its from conic sections

Answer 10

I think it can be done somehow with matrices

Answer 11

but I am not that strong with matrix algebra

Answer 12

nah i definately havent seen something like that