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Se stie ca x+1supra x=4.Calculati:xla puerea 3+1supra x la puerea 3 si x la puterea 4+1 supra x la puterea 4

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Am pus rezolvarea problemei intr-o imagine

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[tex]S=x+\frac{1}{x}=4\\ P=x\cdot\frac{1}{x}=1\\ x^2+\frac{1}{x^2}=S^2-2P=16-2=14\\ x^3+\frac{1}{x^3}=(x+\frac{1}{x})(x^2-x\frac{1}{x}+\frac{1}{x^2})=S(S^2-3P)=4\cdot13=52\\ x^4+\frac{1}{x^4}=(x^2+\frac{1}{x^2})^2-2x^2\frac{1}{x^2}=14^2-2=196-2=194[/tex]