Solve y^2-2d-1=0

$$y ^ { 2 } - 2 d - 1 = 0$$

Solve for d

$$d=\frac{y^{2}-1}{2}$$

Steps for Solving Linear Equation

Subtract y^{2} from both sides. Anything subtracted from zero gives its negation.

$$-2d-1=-y^{2}$$

Add 1 to both sides.

$$-2d=-y^{2}+1$$

The equation is in standard form.

$$-2d=1-y^{2}$$

Divide both sides by -2.

$$\frac{-2d}{-2}=\frac{1-y^{2}}{-2}$$

Dividing by -2 undoes the multiplication by -2.

$$d=\frac{1-y^{2}}{-2}$$

Divide -y^{2}+1 by -2.

$$d=\frac{y^{2}-1}{2}$$

Solve for y (complex solution)

$$y=-\sqrt{2d+1}$$

$$y=\sqrt{2d+1}$$

Solve for y

$$y=\sqrt{2d+1}$$

$$y=-\sqrt{2d+1}\text{, }d\geq -\frac{1}{2}$$