The problem is to simplify the expression $\frac{\sqrt{2}+1}{\sqrt{2}-1}$.

AlgebraSimplificationRationalizationRadicalsAlgebraic Manipulation
2025/3/17

1. Problem Description

The problem is to simplify the expression 2+121\frac{\sqrt{2}+1}{\sqrt{2}-1}.

2. Solution Steps

To simplify the expression, we need to rationalize the denominator. We multiply both the numerator and the denominator by the conjugate of the denominator, which is 2+1\sqrt{2}+1.
2+121=2+1212+12+1\frac{\sqrt{2}+1}{\sqrt{2}-1} = \frac{\sqrt{2}+1}{\sqrt{2}-1} \cdot \frac{\sqrt{2}+1}{\sqrt{2}+1}
Now we multiply the numerators and the denominators:
=(2+1)(2+1)(21)(2+1)= \frac{(\sqrt{2}+1)(\sqrt{2}+1)}{(\sqrt{2}-1)(\sqrt{2}+1)}
The numerator is (2+1)2=(2)2+2(2)(1)+12=2+22+1=3+22(\sqrt{2}+1)^2 = (\sqrt{2})^2 + 2(\sqrt{2})(1) + 1^2 = 2 + 2\sqrt{2} + 1 = 3 + 2\sqrt{2}.
The denominator is (21)(2+1)=(2)212=21=1(\sqrt{2}-1)(\sqrt{2}+1) = (\sqrt{2})^2 - 1^2 = 2 - 1 = 1.
Therefore, the expression becomes:
3+221=3+22\frac{3 + 2\sqrt{2}}{1} = 3 + 2\sqrt{2}

3. Final Answer

3+223+2\sqrt{2}

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