Square Root of 93 - How to Find the Square Root of 93?

#Algebra
TL;DR
The square root of 93 (93\sqrt{93}) is about 9.64379.6437. This article gives the exact radical form, the decimal to four places, the long division method for computing it by hand, why 93\sqrt{93} is irrational, and where the value shows up in geometry.
BT
Bhanzu TeamLast updated on August 17, 20266 min read

What Is A Square Root?

The square root of a number nn is the value rr for which r2=nr^2 = n. So the square root of 93 is the number that, multiplied by itself, gives 93.

No whole number does that. 92=819^2 = 81 is too small, and 102=10010^2 = 100 is too big, so 93\sqrt{93} falls between 9 and 10. Every positive number has two square roots, one positive and one negative, but the symbol 93\sqrt{93} always means the positive, or principal, root.

Where Does √93 Appear?

93\sqrt{93} is the space diagonal of a rectangular box with edges 2, 5, and 8. The 3D version of the Pythagorean theorem gives the diagonal as 22+52+82=4+25+64=93\sqrt{2^2 + 5^2 + 8^2} = \sqrt{4 + 25 + 64} = \sqrt{93}. Because 93 sits between the perfect squares 81=9281 = 9^2 and 100=102100 = 10^2, the value lands between 9 and 10, closer to 10. Anywhere a length is built from squared parts that total 93, this irrational number is the exact answer.

Quick Reference Table

Number nn

n\sqrt{n} (approx.)

Rational or Irrational

81

9

Rational

85

9.2195

Irrational

90

9.4868

Irrational

93

9.6437

Irrational

96

9.7980

Irrational

100

10

Rational

121

11

Rational

Is The Square Root Of 93 Rational Or Irrational?

93\sqrt{93} is an irrational number. It cannot be written as a fraction pq\frac{p}{q} of two integers, and its decimal runs on forever without repeating.

The quick reason comes from the factors. A whole number has a rational square root only when it is a perfect square. Writing 93 as a product of primes gives:

93=3×3193 = 3 \times 31

Both 3 and 31 appear to the first power, so there is no repeated prime to pull out as a pair, and 93 is not a perfect square. That forces 93\sqrt{93} to be irrational. The same style of argument shows every non-perfect-square whole number has an irrational root, the way you can prove that root 3 is irrational or prove that root 7 is irrational by contradiction.

How Do You Find √93? (Long Division Method)

Prime factorization tells you 93\sqrt{93} cannot be simplified, but it does not give the decimal. For that, use long division. Here is the method, one step per line.

Step 1: Write 93 as 93‾.00‾,00‾,00‾\overline{93}.\overline{00},\overline{00},\overline{00}, pairing digits from the decimal point.

Step 2: Find the largest number whose square is at most 93. 92=81≤939^2 = 81 \leq 93 Write 9 as the first digit of the answer.

Step 3: Subtract, then bring down the next pair. 93−81=1293 - 81 = 12 Bring down 0000 to get 12001200.

Step 4: Double the current answer, 9, to get 18. Find a digit dd with (180+d)×d≤1200(180 + d) \times d \leq 1200. 186×6=1116≤1200186 \times 6 = 1116 \leq 1200 The answer is now 9.69.6.

Step 5: Subtract and bring down again. 1200−1116=841200 - 1116 = 84 Bring down 0000 to get 84008400.

Step 6: Double 96 to get 192. Find dd with (1920+d)×d≤8400(1920 + d) \times d \leq 8400. 1924×4=7696≤84001924 \times 4 = 7696 \leq 8400 The answer is now 9.649.64.

Step 7: Continue once more. 8400−7696=7048400 - 7696 = 704 Bring down 0000 to get 7040070400 19283×3=57849≤7040019283 \times 3 = 57849 \leq 70400 The answer is now 9.6439.643.

Carrying the process one more place gives 93≈9.6437\sqrt{93} \approx 9.6437. The division never ends, which is exactly what an irrational value looks like on paper.

Examples Of √93

Example 1

Estimate 93\sqrt{93} to the nearest whole number.

92=819^2 = 81 102=10010^2 = 100 93 is between 81 and 100, so the root is between 9 and 10. Since 93 is closer to 100, round up. Final answer: 10.

Example 2

A student simplifies 93\sqrt{93} as 9×10.33\sqrt{9} \times \sqrt{10.33} and stops. What went wrong?

The wrong path first. Splitting 93 as 9×10.339 \times 10.33 does give 9×10.33=310.33\sqrt{9} \times \sqrt{10.33} = 3\sqrt{10.33}, but 10.3310.33 is not a whole number, so nothing was actually simplified. To simplify a radical you factor out a perfect square that divides the number evenly. 93=3×3193 = 3 \times 31 Neither factor is a perfect square, and no perfect square other than 1 divides 93. Final answer: 93\sqrt{93} is already in simplest form.

Example 3

Evaluate (93)2(\sqrt{93})^2.

By definition, squaring undoes a square root. (93)2=93(\sqrt{93})^2 = 93 Final answer: 93.

Example 4

Find the value of 2932\sqrt{93} to two decimal places.

93≈9.6437\sqrt{93} \approx 9.6437 2×9.6437=19.28742 \times 9.6437 = 19.2874 Round to two places. Final answer: 19.2919.29.

Example 5

A cube-shaped tank has a space diagonal of 93\sqrt{93} metres from combined edges 2, 5, and 8. Confirm the diagonal.

22+52+82=4+25+642^2 + 5^2 + 8^2 = 4 + 25 + 64 =93= 93 diagonal=93≈9.64 m\text{diagonal} = \sqrt{93} \approx 9.64 \text{ m} Final answer: about 9.649.64 metres.

Common Mistakes

Mistake 1: Treating 93 as though it could be simplified

Where it slips in: A learner assumes every radical breaks down into something smaller.

Don't do this: Writing 93=3×31\sqrt{93} = \sqrt{3} \times \sqrt{31} and calling it simpler.

The correct way: That split is valid but not simpler, since neither 3 nor 31 is a perfect square. Most students who reach for a factor pair forget to check that one factor is a perfect square. 93\sqrt{93} stays 93\sqrt{93}.

Mistake 2: Rounding too early

Where it slips in: Multi-step problems where 93\sqrt{93} appears in the middle.

Don't do this: Replacing 93\sqrt{93} with 9.649.64 at the start and carrying that value through every later step.

The correct way: Keep 93\sqrt{93} in radical form until the final step, then round once. Early rounding compounds error across multiplications.

Mistake 3: Forgetting the negative root when solving an equation

Where it slips in: Solving x2=93x^2 = 93.

Don't do this: Writing only x=93x = \sqrt{93}.

The correct way: The equation x2=93x^2 = 93 has two solutions, x=93x = \sqrt{93} and x=−93x = -\sqrt{93}, written together as x=±93x = \pm\sqrt{93}. The bare symbol 93\sqrt{93} still means the positive root alone.

Conclusion

The square root of 93 is an irrational number, about 9.64379.6437, and 93\sqrt{93} is already its simplest form because 93=3×3193 = 3 \times 31 carries no perfect-square factor. Long division gives the decimal to any precision you need, while prime factorization confirms the radical will not reduce. To take radicals further with a teacher, explore Bhanzu's algebra tutor sessions or structured math classes online. You can also book a free demo class to see the approach in action.

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Frequently Asked Questions

What is the value of 93\sqrt{93}?
93≈9.6437\sqrt{93} \approx 9.6437. To seven places it is 9.64365089.6436508, and the decimal never terminates because 93 is not a perfect square.
Is 93 a perfect square?
No. The nearest perfect squares are 81=9281 = 9^2 and 100=102100 = 10^2, and 93 sits between them.
What is 93\sqrt{93} in simplest radical form?
93\sqrt{93}. Since 93=3×3193 = 3 \times 31 has no repeated prime factor, there is nothing to take outside the radical.
Between which two whole numbers does 93\sqrt{93} lie?
Between 9 and 10, and closer to 10.
What is 9.3\sqrt{9.3} if 93≈9.6437\sqrt{93} \approx 9.6437?
Divide by 10\sqrt{10}: 9.3=9310≈9.64373.1623≈3.0496\sqrt{9.3} = \frac{\sqrt{93}}{\sqrt{10}} \approx \frac{9.6437}{3.1623} \approx 3.0496.
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