Question

Find the value of a²+1/a²If a = 9-4√5

Answer 1

Heya !!

Here is ur answer
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⇒a=9-4√5
⇒find
⇒ 1/a= 1/9-4√5×9+4√5/9+4√5
⇒9+4√5/(9)²-(4√5)²
⇒9+4√5

⇒ to find. : a²+1/a²
⇒(9-4√5)²+(9+4√5)²
⇒81+80-72√5+81+80+72√5
⇒72√5 gets cancelled
⇒162+160
⇒322


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Hope this helps you ☺☺

Answer 2

Given that a =9-4√5
Therefore 1/a=1/9-4√5
a^2=9-4√5^2
=81-80
=1
Similary ....
1/a^2=1/1
There fore adding both we get
1+1/1=2
Hope this will help