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If a + (1)/(a) = 2, find (a^(8) +1)...

If a `+ (1)/(a) = 2, ` find
` (a^(8) +1)/(a^(4))`

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The correct Answer is:
To solve the equation \( a + \frac{1}{a} = 2 \) and find the value of \( \frac{a^8 + 1}{a^4} \), we will follow these steps: ### Step 1: Square both sides of the equation Starting with the equation: \[ a + \frac{1}{a} = 2 \] We square both sides: \[ \left(a + \frac{1}{a}\right)^2 = 2^2 \] This simplifies to: \[ a^2 + 2 + \frac{1}{a^2} = 4 \] ### Step 2: Rearrange to find \( a^2 + \frac{1}{a^2} \) From the equation above, we can rearrange it: \[ a^2 + \frac{1}{a^2} = 4 - 2 = 2 \] ### Step 3: Square again to find \( a^4 + \frac{1}{a^4} \) Now we will square \( a^2 + \frac{1}{a^2} \): \[ \left(a^2 + \frac{1}{a^2}\right)^2 = 2^2 \] This expands to: \[ a^4 + 2 + \frac{1}{a^4} = 4 \] Rearranging gives: \[ a^4 + \frac{1}{a^4} = 4 - 2 = 2 \] ### Step 4: Find \( a^8 + \frac{1}{a^8} \) Now we square \( a^4 + \frac{1}{a^4} \): \[ \left(a^4 + \frac{1}{a^4}\right)^2 = 2^2 \] This expands to: \[ a^8 + 2 + \frac{1}{a^8} = 4 \] Rearranging gives: \[ a^8 + \frac{1}{a^8} = 4 - 2 = 2 \] ### Step 5: Calculate \( \frac{a^8 + 1}{a^4} \) Now we need to find \( \frac{a^8 + 1}{a^4} \): \[ \frac{a^8 + 1}{a^4} = \frac{a^8}{a^4} + \frac{1}{a^4} = a^4 + \frac{1}{a^4} \] From Step 3, we found that: \[ a^4 + \frac{1}{a^4} = 2 \] Thus: \[ \frac{a^8 + 1}{a^4} = 2 \] ### Final Answer The value of \( \frac{a^8 + 1}{a^4} \) is \( \boxed{2} \).
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