Solve 1-2=r^2+x

$$1 - 2 = r ^ { 2 } + x$$

Solve for x

$$x=-r^{2}-1$$

Solution Steps

Subtract 2 from 1 to get -1.

$$-1=r^{2}+x$$

Swap sides so that all variable terms are on the left hand side.

$$r^{2}+x=-1$$

Subtract r^{2} from both sides.

$$x=-1-r^{2}$$

Solve for r (complex solution)

$$r=-i\sqrt{x+1}$$

$$r=i\sqrt{x+1}$$

Solve for r

$$r=\sqrt{-x-1}$$

$$r=-\sqrt{-x-1}\text{, }x\leq -1$$