x^2+y^2+2=0?

Question

please help how do you find the square? I do not understand

Answer 1

The answer is that you use imaginary numbers (a number followed by "i" which represents the square root of -1). For example, i^2 + i^2 = -1 + -1 = -2. Add 2 to this and you get 0. There are an infinite combination of values that could work, which you can see if you graph the equation. Set it equal to y, and solve:
y = -sqrt(x^2) - sqrt(2)

Answer 2

This equation can only be satisfied if at least x or y is a non real complex number. There are infinitely (actually, uncountably) many solutions. From the equation, we have

y = sqrt(- 2 - x^2). For each real or non real x, you have 2 complex values for y. For example, if x =0, then y = i sqrt(2) or y = - i sqrt(2).

This is not the equation of a circle.

Answer 3

x^2 + y^2 + 2 = 0 is the equation to an imaginary circle, centered at (0,0) with radius i*sqrt(2).

I bet the concept of a circle with an imaginary radius totally blows your mind, huh?

Answer 4

the radius of the circle is the sqrt(-2)

Since this is basically impossible, it is only possible in an imaginary graph... therefore, the circle, which would be centered at (0,0), doesn't exist.