Question

If
$a - \frac{1}{a } = 7$
then what is the value of
${a}^{4} + \frac{1} {a}^{4}$
?
Please help me with this one.. don't spam otherwise 10 of your answers will be reported..​

Answer 1

Step-by-step explanation. 2599

a- 1/a= 7

square it : keeping squared multiplicative inverse addition on LHS

a^2+1/a^2-2=49

a^2+1/a^2. =51

square the equation again:

a^4+ 1/a^4 +2= 51^2= 2601

a^4+ 1/a^4 =2601-2 =2599

Answer 2

Answer:

a- 1/a= 7

square it : keeping squared multiplicative inverse addition on LHS

a^2+1/a^2-2=49

a^2+1/a^2. =51

square the equation again:

a^4+ 1/a^4 +2= 51^2= 2601

a^4+ 1/a^4 =2601-2 =2599

Explanation:

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