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If x^2+2=3^2/3+3^-2/3 then prove that 3x^3+9x-8=0​

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here is the solution

If x^2+2=3^2/3+3^-2/3 then prove that 3x^3+9x-8=0​-example-1
User Rob Wright
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Answer:

See below.

Explanation:

x^2 + 2 = 3^2/3 + 3^-2/3

x^2 = 3^2/3 + 3^-2/3 - 2

x = √(3^2/3 + 3^-2/3 - 2)

x = 0.748888296

Substitute for x in 3x^3 + 9x - 8:

3( 0.748888296)^3 + 9( 0.748888296) - 8 = 0.

So it is proved.

User AdamBT
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