Solve x^2-4 = 0

Solve ax² + bx + c = 0 using the quadratic formula with discriminant analysis.

Equation

Answer

x = ±2

x²-4=0

Solve by isolating x² and taking the square root of both sides:

Step 1 — Isolate x²

Move the constant to the other side by adding 4:

x² = 4

Step 2 — Take the square root of both sides

Since x² = k has two solutions, x = +√k and x = −√k:

x = ±√4

x = ±2

How to solve x^2-4 = 0

To solve x^2-4 = 0, we can try factoring, use the quadratic formula, or complete the square. The solution is x = ±2.

This is a second-degree quadratic equation — the highest power of the variable is 2. Quadratic equations can have two real roots, one repeated root, or two complex roots.

Frequently asked questions

What is the answer to x^2-4 = 0?
The answer is x = ±2.

What method is used?
factoring when possible, or the quadratic formula x = (−b ± √(b²−4ac)) / 2a. The discriminant b²−4ac determines the number and type of solutions.

How do I verify this?
Substituting the solution(s) back into x^2-4 = 0 confirms both sides are equal.

More quadratic formula calculator problems

x² + 5x + 6 = 0 x² − 4 = 0 2x² − 3x − 2 = 0 x² + 2x − 8 = 0 x² − 6x + 9 = 0 3x² + x − 2 = 0 x² − 9 = 0 x² + 4x + 4 = 0 x² − x − 12 = 0 4x² − 1 = 0 x² + 3x = 10 2x² = 18