find the value of x3 +1/x3 if x+1/x =2
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Answer:
please mark me as breainist answer
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Step-by-step explanation:
Let p (x) = x + 1 / x = 2
= x + 1 = 2x
= 2x - x = 1
or, x = 1.
let g(x) = x^3 + 1/x^3
since, x = 1
therefore,
g (1) = (1)^3 +1 / (1)^3
= 1 + 1 / 1
= 2 / 1
= 2
So, the answer to your question is 2.
You can also make it this way -
x + 1/ x = 2
Cubing both sides, we get -
x^3 + 1/x^3 + 3×x×1/x (x + 1/x) = 8
= x^3 + 1/x^3 + 3 (x + 1/x) = 8
= x^3 + 1/x^3 + 3 × 2 = 8 (since, x + 1/ x = 2)
= x^3 + 1/x^3 = 8 - 6
or, x^3 + 1/x^3 = 2.
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