Question

3D Vector thingies

Answer 1

We were given a problem where we were given the expanded version of a sphere formula but then we needed to find the radius and center of the sphere.

Answer 2

\[x^2+y^2+z^2+2x-2y=2\]

Answer 3

I understand how to complete the square, but I am not fully aware of what to do with the numbers when you find it.
I got the formula as \[(x+1)^2+(y-1)^2+z^2\]

Answer 4

I can't find the radius while I know the center is (-1, 1, 0).
How would you find the radius?

Answer 5

@dude @shadow @vocaloid

Answer 6

you forgot the RHS

\(x^2+y^2+z^2+2x-2y=2\)

complete the square *properly*

\(x^2+2x+y^2-2y +z^2=2\)

Answer 7

?

Answer 8

\((x+1)^2 - 1 +(y - 1)^2 - 1 + z^2 = 2\)

Answer 9

the ***RHS***

Answer 10

Yeah so wouldn't the radius be four?

Answer 11

2-squared, innit

Answer 12

\((x+1)^2 - 1 +(y - 1)^2 - 1 + z^2 = 2\)

\((x+1)^2 +(y - 1)^2 + z^2 = 2^2 = R^2\)

Answer 13

oh. thanks xD

Answer 14

I forgot we had to square it.

Answer 15

cool!