Question

if a=9-4√5 then find the value of (a-1/a)^2​

Answer 1

Answer:

1

hope this helps you....

Answer 2

Hii..

Given:- a =9 - 4√5

Firstly rationalising ,

=> 1/a = 1 / [ 9-(4√5) ]

=> 1/a = 9 + (4 √5) / (81-16*5)

=> 1/a = ( 9 + ( 4√5 ) / (81 - 80)

=> 1/a = ( 9 + [ 4√5 ] ) / 1

=> 1/a = 9 + 4√5

Now, substituting the value of 1/a

=> 9 - (4√5) - [9 + 4√5]

=> 9 -( 4√5) - 9 - (4√5)

( 9 will cancel out )

=> - 8√5

I hope this helps..☺️✌️