Question

10.If x= 2+√3 then x+ 1/x is: (1 Point) )0 a ) 0 )2 b ) 2 )4 c ) 4 )23−−√ d ) 2 3

Answer 1

x+1/x

=(2+√3)+1/(2+√3)

=(2+√3)(2+√3)+1÷(2+√3)

=4+2√3+2√3+3+1÷(2+√3)

=(8+4√3)÷(2+√3)

=4(2+√3)/(2+√3)

=4