Fourth Root Calculator (⁴√x)

Calculate the fourth root (also known as quartic root) of any number with precision. This calculator handles both positive and negative numbers, identifies perfect fourth roots, and provides detailed step-by-step solutions.

Perfect Fourth Roots:

• 1 → 1

• 16 → 2

• 81 → 3

• 256 → 4

• 625 → 5

• 1,296 → 6

• 2,401 → 7

• 4,096 → 8

• 6,561 → 9

• 10,000 → 10

What is a Fourth Root?

The fourth root of a number is a value that, when raised to the fourth power, equals the original number. For example, 2 is the fourth root of 16 because 2⁴ = 16. Fourth roots are also known as quartic roots or biquadratic roots.

If ⁴√x = n, then n⁴ = x

⁴√16 = 2 because 2⁴ = 16

⁴√81 = 3 because 3⁴ = 81

Example Calculations

Perfect Fourth Roots

Small Numbers

  • ⁴√1 = 1 (since 1⁴ = 1)
  • ⁴√16 = 2 (since 2⁴ = 16)
  • ⁴√81 = 3 (since 3⁴ = 81)
  • ⁴√256 = 4 (since 4⁴ = 256)
  • ⁴√625 = 5 (since 5⁴ = 625)

Larger Numbers

  • ⁴√1,296 = 6 (since 6⁴ = 1,296)
  • ⁴√2,401 = 7 (since 7⁴ = 2,401)
  • ⁴√4,096 = 8 (since 8⁴ = 4,096)
  • ⁴√6,561 = 9 (since 9⁴ = 6,561)
  • ⁴√10,000 = 10 (since 10⁴ = 10,000)

Real-World Applications

Engineering

  • Waveform analysis
  • Signal processing
  • Mechanical resonance
  • Electrical circuit analysis

Mathematics

  • Quartic equations
  • Complex number theory
  • Geometric calculations
  • Polynomial factorization

Non-Perfect Fourth Roots

Irrational Results

⁴√50 ≈ 2.659240142516914

Verify:

(2.659240142516914)⁴ = 50

Properties of Fourth Roots

  • Every positive real number has exactly one positive real fourth root
  • Negative numbers have no real fourth roots (only complex roots)
  • Perfect fourth powers have rational fourth roots
  • Most fourth roots result in irrational numbers
  • The fourth root function is strictly increasing for positive numbers
  • Fourth roots are equivalent to taking a square root twice

Special Cases and Tips

  • The fourth root of 0 is 0
  • Negative numbers have no real fourth roots
  • ⁴√(x⁴) = |x| for any real number x
  • ⁴√(a·b) = ⁴√a · ⁴√b for positive numbers
  • ⁴√(1/x) = 1/⁴√x for positive numbers