Question

a = 9-4√5 , a^2 + 1/a^2

Answer 1

Answer:

Step-by-step explanation:

Answer 2

We know that

$a = 9 - 4 \sqrt{5}$

therefore,

${a}^{2} = ( 9 - 4 \sqrt{5} ) {}^{2}$

and also

$( \frac{1}{?9 - 4 \sqrt{5 {}^{} } } ){}^{2}$

that is 81-80

so a^2+1÷a^2

$= \frac{2}{1}$

that is,1