How to simplify sqrt(2)/(sqrt(2) - 1) to 2 + sqrt(2)

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In summary, to simplify sqrt(2)/(sqrt(2) - 1) to 2 + sqrt(2), we use the difference of squares formula which allows us to convert the division of two square roots into a sum of two square roots. This is because it helps us to eliminate the radical sign and simplify the expression to a more manageable form. We cannot simplify this expression to a whole number as the simplified form of 2 + sqrt(2) is an irrational number. While we can use a calculator to verify the simplification, it is important to understand the mathematical concepts behind it. Another method is to rationalize the denominator, but the difference of squares formula is the most efficient method for this expression.
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negatifzeo
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Homework Statement


I feel really stupid asking this, but I'm working on infinite series and my answer is sqrt(2)/(sqrt(2)-1) The book simplifies this to 2 + sqrt(2) and I don't know how this simplification occurs. I'm sure the answer is really obvious and I sure feel stupid not seeing it! Any help is appreciated.

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The Attempt at a Solution

 
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  • #2


nevermind, I see now that it was the conjugate... :)
 
  • #3
First, let's rewrite sqrt(2) as 2^(1/2):

sqrt(2)/(sqrt(2) - 1) = 2^(1/2)/((2^(1/2)) - 1)

Next, we can use the formula for difference of squares, (a^2 - b^2) = (a+b)(a-b), to simplify the denominator:

2^(1/2)/((2^(1/2)) - 1) = 2^(1/2)/((2^(1/2)) - 1) * ((2^(1/2)) + 1)/((2^(1/2)) + 1)

= (2^(1/2) * (2^(1/2) + 1))/((2^(1/2))^2 - 1)

= (2^(1/2) * (2^(1/2) + 1))/(2 - 1)

= (2^(1/2) * (2^(1/2) + 1))/1

= 2^(1/2) * (2^(1/2) + 1)

= 2 + 2^(1/2)

= 2 + sqrt(2)

Therefore, sqrt(2)/(sqrt(2) - 1) simplifies to 2 + sqrt(2).

In general, when simplifying fractions with square roots in the denominator, we can use the difference of squares formula to get rid of the square root in the denominator and simplify the expression.
 

1. How do you simplify sqrt(2)/(sqrt(2) - 1) to 2 + sqrt(2)?

To simplify this expression, we can use the difference of squares formula which states that (a + b)(a - b) = a^2 - b^2. In this case, a is sqrt(2) and b is 1. Therefore, we can rewrite the expression as (sqrt(2) + 1)(sqrt(2) - 1). Using the formula, we get (2 - 1) which simplifies to 1. This leaves us with the simplified expression of 2 + sqrt(2).

2. Why do we use the difference of squares formula to simplify this expression?

The difference of squares formula is used to simplify expressions involving square roots. It allows us to eliminate the radical sign and simplify the expression to a more manageable form. In this case, it helps us to convert the division of two square roots into a sum of two square roots, making it easier to evaluate the expression.

3. Can we simplify sqrt(2)/(sqrt(2) - 1) to a whole number?

No, we cannot simplify this expression to a whole number. The simplified form of 2 + sqrt(2) is an irrational number, which means it cannot be expressed as a fraction or a whole number. This is because the original expression contains an irrational number (sqrt(2)) and dividing it by another irrational number (sqrt(2) - 1) will result in an irrational number.

4. Can we use a calculator to simplify sqrt(2)/(sqrt(2) - 1) to 2 + sqrt(2)?

Yes, we can use a calculator to verify the simplification of this expression. However, it is important to note that calculators may not always give the exact simplified form because they use approximations. It is always best to understand the mathematical concepts behind the simplification process.

5. Are there any other methods to simplify sqrt(2)/(sqrt(2) - 1) to 2 + sqrt(2)?

Yes, there are other methods to simplify this expression. One method is to rationalize the denominator by multiplying both the numerator and denominator by the conjugate of the denominator, which in this case is sqrt(2) + 1. This will eliminate the square root in the denominator, and we will be left with 2 + sqrt(2). However, the difference of squares formula is the most efficient method to simplify this particular expression.

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