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If x+ (1)/(x)=1, find x^(9) + (1)/(x^...

If `x+ (1)/(x)=1`, find
`x^(9) + (1)/(x^(9))=`

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To solve the equation \( x + \frac{1}{x} = 1 \) and find \( x^9 + \frac{1}{x^9} \), we can follow these steps: ### Step 1: Cube both sides of the equation We start with the equation: \[ x + \frac{1}{x} = 1 \] Cubing both sides gives us: \[ \left( x + \frac{1}{x} \right)^3 = 1^3 \] This expands to: \[ x^3 + 3x \cdot \frac{1}{x} \cdot \left( x + \frac{1}{x} \right) + \frac{1}{x^3} = 1 \] ### Step 2: Simplify the equation The term \( 3x \cdot \frac{1}{x} \) simplifies to \( 3 \), and since \( x + \frac{1}{x} = 1 \), we can substitute: \[ x^3 + 3 \cdot 1 + \frac{1}{x^3} = 1 \] This simplifies to: \[ x^3 + \frac{1}{x^3} + 3 = 1 \] ### Step 3: Isolate \( x^3 + \frac{1}{x^3} \) Now, we can isolate \( x^3 + \frac{1}{x^3} \): \[ x^3 + \frac{1}{x^3} = 1 - 3 \] Thus, \[ x^3 + \frac{1}{x^3} = -2 \] ### Step 4: Find \( x^9 + \frac{1}{x^9} \) To find \( x^9 + \frac{1}{x^9} \), we can use the identity: \[ x^9 + \frac{1}{x^9} = \left( x^3 + \frac{1}{x^3} \right)^3 - 3 \left( x^3 + \frac{1}{x^3} \right) \] Substituting \( x^3 + \frac{1}{x^3} = -2 \): \[ x^9 + \frac{1}{x^9} = (-2)^3 - 3(-2) \] ### Step 5: Calculate the values Calculating \( (-2)^3 \): \[ (-2)^3 = -8 \] And calculating \( -3(-2) \): \[ -3(-2) = 6 \] Now substituting back: \[ x^9 + \frac{1}{x^9} = -8 + 6 = -2 \] ### Final Answer Thus, the final result is: \[ \boxed{-2} \]
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