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If x+(1)/(x)=1 then x^(52)+x^(46)+x^(32...

If `x+(1)/(x)=1` then `x^(52)+x^(46)+x^(32)+x^(26)+x^(21)+x^(15)+x^(6)+x^(3)+4` is equal to

A

0

B

3

C

4

D

2

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The correct Answer is:
To solve the equation \( x + \frac{1}{x} = 1 \) and find the value of the expression \( x^{52} + x^{46} + x^{32} + x^{26} + x^{21} + x^{15} + x^{6} + x^{3} + 4 \), we can follow these steps: ### Step 1: Rearranging the Initial Equation Starting with the equation: \[ x + \frac{1}{x} = 1 \] We can multiply both sides by \( x \) (assuming \( x \neq 0 \)): \[ x^2 + 1 = x \] Rearranging gives us: \[ x^2 - x + 1 = 0 \] ### Step 2: Finding Roots of the Quadratic Equation To find the roots of the quadratic equation \( x^2 - x + 1 = 0 \), we can use the quadratic formula: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \( a = 1, b = -1, c = 1 \): \[ x = \frac{1 \pm \sqrt{(-1)^2 - 4 \cdot 1 \cdot 1}}{2 \cdot 1} = \frac{1 \pm \sqrt{1 - 4}}{2} = \frac{1 \pm \sqrt{-3}}{2} \] This gives us: \[ x = \frac{1 \pm i\sqrt{3}}{2} \] ### Step 3: Finding \( x^3 \) Next, we can find \( x^3 \) using the identity: \[ x^3 = (x + \frac{1}{x}) \cdot (x^2) - 1 \] From \( x + \frac{1}{x} = 1 \), we have: \[ x^3 = 1 \cdot (x^2) - 1 = x^2 - 1 \] Using \( x^2 = x - 1 \) (from the quadratic equation), we substitute: \[ x^3 = (x - 1) - 1 = x - 2 \] ### Step 4: Finding Higher Powers of x We can express higher powers of \( x \) in terms of \( x \) and constants. Notably: - \( x^3 = -1 \) - \( x^6 = (x^3)^2 = (-1)^2 = 1 \) Thus, we can find: \[ x^{52} = (x^6)^8 \cdot x^4 = 1^8 \cdot x^4 = x^4 \] \[ x^{46} = (x^6)^7 \cdot x^4 = 1^7 \cdot x^4 = x^4 \] \[ x^{32} = (x^6)^5 \cdot x^2 = 1^5 \cdot x^2 = x^2 \] \[ x^{26} = (x^6)^4 \cdot x^2 = 1^4 \cdot x^2 = x^2 \] \[ x^{21} = (x^6)^3 \cdot x^3 = 1^3 \cdot x^3 = x^3 \] \[ x^{15} = (x^6)^2 \cdot x^3 = 1^2 \cdot x^3 = x^3 \] \[ x^{6} = 1 \] \[ x^{3} = -1 \] ### Step 5: Substituting Back into the Expression Now substituting these back into the expression: \[ x^{52} + x^{46} + x^{32} + x^{26} + x^{21} + x^{15} + x^{6} + x^{3} + 4 \] becomes: \[ x^4 + x^4 + x^2 + x^2 + x^3 + x^3 + 1 - 1 + 4 \] Combining like terms: \[ 2x^4 + 2x^2 + 2(-1) + 4 = 2x^4 + 2x^2 + 2 \] ### Step 6: Finding the Value of \( x^4 \) and \( x^2 \) Using \( x^2 = x - 1 \): \[ x^4 = (x^2)^2 = (x - 1)^2 = x^2 - 2x + 1 = (x - 1) - 2x + 1 = -x + 2 \] Thus: \[ 2x^4 + 2x^2 + 2 = 2(-x + 2) + 2(x - 1) + 2 = -2x + 4 + 2x - 2 + 2 = 4 \] ### Final Answer The value of the expression is: \[ \boxed{4} \]
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