If a2 – 1/a2 = 5, evaluate a4 + 1/a4
Answer :
It is given that,
a2 – 1/a2 = 5
So,
By using the formula, (a + b)2
[a2 – 1/a2]2 = a4 + 1/a4 – 2
[a2 – 1/a2]2 + 2 = a4 + 1/a4
Substitute the value of a2 – 1/a2 = 5, we get
52 + 2 = a4 + 1/a4
a4 + 1/a4 = 25 + 2
= 27
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