If you checked the definition, you'll get (-1,0).

We call the x-axis, which is all points (x,0), the "real numbers." They act just like the numbers of our number line, since

(a,0)*(b,0)=(a*b,0)

and

(a,0)+(b,0)=(a+b,0).

We call the y-axis the imaginary numbers, and call the whole plane's worth of points the complex numbers, or the complex plane.

We define "i," the imaginary unit, to be (0,1) so that we may write

(a,b)=a+bi.

What is i^2 (i.e., what is i times i)?