Question

does anyone know a general statement for something in cartesian form?

Answer 1

For complex numbers? a +/- bi

Answer 2

for a circle it is x^2+y^2 = r^2

Answer 3

hm ok

i've got z = 3+i / 3-i

Answer 4

multiply the numerator and denominator by the conjugate of 3-i

Answer 5

(3+i)^2 / 9-i^2

Answer 6

i^2 = -1

Answer 7

so it is (3+i)^2 /10

Answer 8

or (8+6i)/10

Answer 9

Or (4/5) + (3/5)i...standard form

Answer 10

gah
so intuitive i miss it

Answer 11

heh, it happens to all of some time or the other :)

Answer 12

i feel like it happens to me all the time, do you know anything i could practice to stop that?

Answer 13

I guess it takes time not to miss these things. In general, if you are dealing with complex numbers, keep a checklist of things you should be on the lookout for
1) conjugates
2) i^2 =-1
that sort of thing.

Answer 14

and everything i've learnt previously :(