if x^4+1/x^4=119 find x-1/x
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Answered by
22
Adding 2 on both sides;
x^4 + 1/x^4 +2 = 119 +2
(x²+1/x²)²=121
x²+1/x²=11
Adding -2 on both sides
x²-2+1/x²=9
(x-1/x)²= 9
x-1/x= ±3
Now, (x-1/x)³= x³-1/x³-3(x-1/x)
Consider x-1/x= 3 .
3³ = x³-1/x³-3(3)
27= x³-1/x³ - 9
27+9=x³-1/x³
36 = x³-1/x³
consider x-1/x = -3
-27 = x³-1/x³-3(-3)
-27 = x³-1/x³+9
-27-9 = x³-1/x³
x³-1/x³ = ±36
Answered by
4
Answer:
+-3
Step-by-step explanation:
this is correct answer
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