if x+1/x =3/2 , then the value of 8x³+1/8x³ wil be
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Answered by
0
Answer:
Given: (x)+(1/x)=3/2
(4x^2+1)/2x=3/2
4x^2+1=6x
4x^2-6x+1=0
By formula method
x=(3+root5)/4 and (3-root5)/4
And we know that :root 5=2.23 (approx)
So,
x=1.3 and 0.2
Now,
(x^3)+(1/8x^3)=?
First we put x=1.3 then we get
=2.15
And when we put x=0.2 then we get
=15.6
Answered by
0
Answer:
-9
Step-by-step explanation:
Given: x+1/x =3/2 ... (1)
To obtain 8, we first need to multiply 2.
2(x + 1/x) = 3
We can get 8(x³ + 1/x³) after cubing both sides.
8(x³ + 3x + 3/x + 1/x³) = 27
From (1)
8(x³ + 9/2 + 1/x³) = 27
8(x³ + 1/x³) + 36 = 27
∴8(x³ + 1/x³) = -9
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