Question

If X= 7-4√3 , find i. X+1/X ,ii.x-1/X

Answer 1

1)

x= 7-4√3

x+1/x = (7-4√3) + 1/(7-4√3)

=7-4√3+(7+4√3)/(49-48)

=7-4√3 + (7+4√3)/1

= 7-4√3+7+4√3

=14

x-1/x = (7-4√3) - 1/(7-4√3)

= 7-4√3 - (7+4√3)/(49-48)

= 7-4√3 - 7-4√3

= - 8√3