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If a + (1)/(a) = 2, find (a^(4) + 1...

If a `+ (1)/(a) = 2, ` find
` (a^(4) + 1)/(a^(2))`

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The correct Answer is:
To solve the equation \( a + \frac{1}{a} = 2 \) and find \( \frac{a^4 + 1}{a^2} \), we can follow these steps: ### Step 1: Square both sides of the equation Starting with the equation: \[ a + \frac{1}{a} = 2 \] We will square both sides: \[ \left(a + \frac{1}{a}\right)^2 = 2^2 \] This simplifies to: \[ a^2 + 2 \cdot a \cdot \frac{1}{a} + \frac{1}{a^2} = 4 \] Which simplifies to: \[ a^2 + 2 + \frac{1}{a^2} = 4 \] ### Step 2: Rearrange the equation Now, we can rearrange the equation to isolate \( a^2 + \frac{1}{a^2} \): \[ a^2 + \frac{1}{a^2} = 4 - 2 \] This gives us: \[ a^2 + \frac{1}{a^2} = 2 \] ### Step 3: Find \( a^4 + 1 \) Next, we need to find \( a^4 + 1 \). We can use the identity: \[ a^4 + 1 = (a^2)^2 + 1 \] We can express \( a^4 + 1 \) in terms of \( a^2 + \frac{1}{a^2} \): \[ a^4 + 1 = a^4 + \frac{1}{a^2} \cdot a^2 = a^4 + a^2 \cdot \frac{1}{a^2} \] Using the identity \( a^2 + \frac{1}{a^2} = 2 \), we can find \( a^4 + 1 \): \[ a^4 + 1 = (a^2 + \frac{1}{a^2})^2 - 2 \cdot a^2 \cdot \frac{1}{a^2} \] Substituting \( a^2 + \frac{1}{a^2} = 2 \): \[ = 2^2 - 2 = 4 - 2 = 2 \] ### Step 4: Find \( \frac{a^4 + 1}{a^2} \) Now, we can find \( \frac{a^4 + 1}{a^2} \): \[ \frac{a^4 + 1}{a^2} = \frac{2}{a^2} \] Since we know \( a^2 + \frac{1}{a^2} = 2 \), we can find \( a^2 \): \[ a^2 = 1 \quad \text{(since } a + \frac{1}{a} = 2 \text{ implies } a = 1 \text{)} \] Thus: \[ \frac{2}{1} = 2 \] ### Final Answer Therefore, the value of \( \frac{a^4 + 1}{a^2} \) is: \[ \boxed{2} \]
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