Calcolatore di radice quadrata e semplificatore di radicali

Square root calculator: the root to up to 1,000 decimal places, simplest radical form (√72 = 6√2), a perfect-square check and cube or nth roots.

Aggiornato Esempi verificati: 9

A whole number, decimal or fraction, e.g. 72, 0.72 or 18/25.
2 for the square root, 3 for the cube root, any whole number up to 100 for other roots.
How many digits to show after the decimal point (up to 1,000). Digits are truncated, not rounded.
Prova
Root
Root: 8.48528137424
Cifre significative: 12; Al più vicino; a parità lontano da zero
Simplest radical form
6√2
Perfect power?
No: 8² = 64 < 72 < 81 = 9²
Negative root
−8.48528137424

The square root of 72 is about 8.48528137, which simplifies exactly to 6√2. It lies between 8 and 9 because 72 lies between 64 and 81.

√72 to 30 decimal places

8.4852813742 3857029281 0132345258

Truncated after 30 decimal places; the next digit is 1.

y = √x between the perfect squares either side

88.5965707580x√x8² = 649² = 81√72 ≈ 8.4853
Prime factors of 72 Righe: 2
PrimeExponentGroups of 2 (come out)Left inside
2311
3210
Come si calcola S
  1. Prime factorization

    72=23×3272 = 2^{3} \times 3^{2}

    Each prime's exponent is split into complete groups of 2 and a leftover.

  2. Take out groups of 2

    72=62×2=62\sqrt{72} = \sqrt{6^{2} \times 2} = 6\sqrt{2}

    No prime appears 2 times in 2, so the radical is fully simplified.

  3. Decimal value

    72≈8.48528137423857\sqrt{72} \approx 8.48528137423857

    Computed with exact integer arithmetic; the digits panel shows 30 decimal places.

  4. Is it a perfect square?

    82=64<72<81=928^{2} = 64 < 72 < 81 = 9^{2}

    72 lies strictly between two consecutive perfect squares, so its square root is between 8 and 9 and is irrational.

Informazioni su Calcolatore di radice quadrata e semplificatore di radicali

The square root of x is the non-negative number that gives x when multiplied by itself; the nth root does the same with n equal factors. The calculator takes the root with exact whole-number arithmetic, so every digit shown is correct, and simplifies the radical by prime factorization: write the number as a product of prime powers, move each complete group of n equal primes outside the root sign, and leave the rest inside.

For 72 = 2³ × 3², one pair of 2s and one pair of 3s come out as 2 × 3 = 6, and one 2 stays inside, so √72 = 6√2 ≈ 8.485281. Since 8² = 64 and 9² = 81, 72 is not a perfect square. Fractions and decimals work too: √0.72 = √(18/25) = 3√2/5.

Digits are truncated, not rounded, and up to 1,000 decimal places are available. An even root of a negative number is not a real number; odd roots of negative numbers are, as ∛(−54) = −3∛2.

Esempi svolti

√72 (default)

Number
72
Root
2
Decimal places
30
Root
8.48528137424
Simplest radical form
6√2
Perfect power?
No: 8² = 64 < 72 < 81 = 9²
Negative root
-8.48528137424

Fonte di verifica: OpenStax Elementary Algebra 2e §9.2: √72 = 6√2; Python decimal (60 digits) Decimal(72).sqrt() = 8.4852813742385702928…

√27 (calculator.net and OpenStax)

Number
27
Root
2
Decimal places
30
Root
5.196
Simplest radical form
3√3

Fonte di verifica: calculator.net root calculator example: √27 = 5.196 to 3 places; OpenStax §9.2: √27 = 3√3

√52 (Omni Calculator example)

Number
52
Root
2
Decimal places
30
Root
7.2111
Simplest radical form
2√13

Fonte di verifica: Omni Calculator square root page: √52 = 2√13 ≈ 7.22 (7.2111025509… by Python Decimal(52).sqrt())

Cube root of 54

Number
54
Root
3
Decimal places
30
Root
3.77976314968
Simplest radical form
3∛2
Perfect power?
No: 3³ = 27 < 54 < 64 = 4³
Negative root
non applicabile

Fonte di verifica: 54 = 2 × 3³; Python decimal: Decimal(54) ** (Decimal(1) / 3) = 3.7797631496846193…

Domande

How do you simplify a square root?

Factor the number into primes, pair up equal primes, and move one of each pair outside the root. 72 = 2 × 2 × 2 × 3 × 3 has a pair of 2s and a pair of 3s, so 2 × 3 = 6 comes out and one 2 stays in: √72 = 6√2. Equivalently, split off the largest perfect square factor: 72 = 36 × 2, and √36 = 6. A root is simplified when nothing under the sign has a square factor (OpenStax Elementary Algebra 2e, §9.2).

How do you know if a number is a perfect square?

A whole number is a perfect square when every exponent in its prime factorization is even, or equivalently when its square root is a whole number. 144 = 2⁴ × 3² is 12², while 72 = 2³ × 3² is not, because the exponent of 2 is odd. Perfect squares also end only in 0, 1, 4, 5, 6 or 9, so a number ending in 2, 3, 7 or 8, such as 72, can be ruled out at a glance.

What is the square root of 2 to 50 decimal places?

√2 = 1.41421356237309504880168872420969807856967187537694, truncated after 50 decimal places. The digits never end or repeat, because √2 is irrational: it is not a ratio of two whole numbers. The ISO 216 paper sizes use it, so an A4 sheet's sides are in the ratio 297/210 = 1.414.

How do you find the cube root or nth root of a number?

The nth root of x is the number that, used n times as a factor, gives x. To simplify it, take out every complete group of n equal primes: 54 = 2 × 3³, so ∛54 = 3∛2 ≈ 3.779763. For an nth root with a decimal answer, raise x to the power 1/n; calculator.net's example gives the 8th root of 15 as 1.403 to three places.

Why does a positive number have two square roots?

Because a negative times a negative is positive: 8.485…² and (−8.485…)² both equal 72. The radical sign √ means the principal, non-negative root, so √72 = 6√2 and the other root is −6√2; together they are written ±6√2. Solving x² = 72 therefore gives two answers. Odd roots have only one real value, and ∛(−8) = −2.

Quanto è preciso «Calcolatore di radice quadrata e semplificatore di radicali»?

La precisione dipende dai dati inseriti e dalle ipotesi del metodo. Il calcolo decimale usa 50 cifre significative, ma stime, metodi numerici e dati di origine possono essere meno precisi; l’arrotondamento visualizzato non elimina questi limiti. Esempi svolti verificati con fonti indipendenti: 9. Per esempio, «√72 (default)» viene verificato con OpenStax Elementary Algebra 2e §9.2: √72 = 6√2; Python decimal (60 digits) Decimal(72).sqrt() = 8.4852813742385702928….

Da dove proviene il metodo?

OpenStax, Elementary Algebra 2e, §9.2 Simplify square roots (√72 = 6√2, √27 = 3√3); Wolfram MathWorld: Square root; Wolfram MathWorld: Pythagoras's constant (digits of √2).

Informazioni su questa calcolatrice

anbn=abnpqn=p q n−1nq\sqrt[n]{a^{n} b} = a\sqrt[n]{b} \qquad \sqrt[n]{\frac{p}{q}} = \frac{\sqrt[n]{p\,q^{\,n-1}}}{q}

Fonti

  1. OpenStax, Elementary Algebra 2e, §9.2 Simplify square roots (√72 = 6√2, √27 = 3√3)
  2. Wolfram MathWorld: Square root
  3. Wolfram MathWorld: Pythagoras's constant (digits of √2)

Verificato con le fonti

Questa calcolatrice include 9 esempi svolti con risposte da fonti indipendenti. Fanno parte della suite di test e puoi eseguirli anche qui.

Calcolatrici correlate