Quadratic Equations

Find roots instantly using Sutras.

Core Concepts

A quadratic equation looks like ax² + bx + c = 0. The goal is to find values of x (called roots) that make the equation zero.

The Factor Trick

For x² + 5x + 6 = 0:
Find two numbers that multiply to 6 and add to 5.
They are 2 and 3.
So factors are (x+2)(x+3).

Finding Roots

If factors are (x+2) and (x+3), just flip the signs!
Roots are -2 and -3.
"If (x-4) is a factor, x=4 is a root."

Solved Examples

Example 1: x² + 5x + 6 = 0

Question: Find roots.

• Product = 6, Sum = 5.

• Numbers are 2 and 3.

• Factors: (x+2)(x+3).

• Roots: -2, -3.

Example 2: x² - 5x + 6 = 0

Question: Find roots.

• Product = 6, Sum = -5.

• Numbers are -2 and -3.

• Factors: (x-2)(x-3).

• Roots: 2, 3.

Example 3: x² - 9 = 0

Question: Find roots.

• This is x² = 9.

• Square root of 9 is 3.

• Roots: 3, -3.

Example 4: (x-5)(x+1) = 0

Question: Find roots.

• If x-5 = 0, then x = 5.

• If x+1 = 0, then x = -1.

• Roots: 5, -1.

Quadratic Equations Chart