Question

if a=9+4 root 5 find (a) a+1/a (b) a-1/a
pls answer fast ​

Answer 1

Answer:

In this question,

a=9+4root5

For 1/a we have to rationalise the denominators

so the result after rationalising = 9+4root5

a-1/a = 9-4root5 -(9+4root5)

= -4root5 -4root5

= -8root5.