Solve 2x^2=-128

$$2 x ^ { 2 } = - 128$$

Solve for x (complex solution)

$$x=-8i$$

$$x=8i$$

Steps by Finding Square Root

Divide both sides by 2.

$$x^{2}=\frac{-128}{2}$$

Divide -128 by 2 to get -64.

$$x^{2}=-64$$

The equation is now solved.

$$x=8i x=-8i$$

Steps Using the Quadratic Formula

Divide both sides by 2.

$$x^{2}=\frac{-128}{2}$$

Divide -128 by 2 to get -64.

$$x^{2}=-64$$

Add 64 to both sides.

$$x^{2}+64=0$$

This equation is in standard form: ax^{2}+bx+c=0. Substitute 1 for a, 0 for b, and 64 for c in the quadratic formula, \frac{-b±\sqrt{b^{2}-4ac}}{2a}.

$$x=\frac{0±\sqrt{0^{2}-4\times 64}}{2}$$

Square 0.

$$x=\frac{0±\sqrt{-4\times 64}}{2}$$

Multiply -4 times 64.

$$x=\frac{0±\sqrt{-256}}{2}$$

Take the square root of -256.

$$x=\frac{0±16i}{2}$$

Now solve the equation x=\frac{0±16i}{2} when ± is plus.

$$x=8i$$

Now solve the equation x=\frac{0±16i}{2} when ± is minus.

$$x=-8i$$

The equation is now solved.

$$x=8i x=-8i$$