Question

If x=(4-√15) find the value of (x+1/x)

Answer 1

Ans.. this can be solved by the method of rationalisation. so after this

ans is 8

Answer 2

given,x=(4-√15)

therefore, 1/x=1/(4-√15)=>1/x=4+√15/(4-√15)(4+√15)=>1/x=4+√15[since(4-√15)(4+√15) is 1 by a²-b². therefore,16-15=1]

therefore,x+1/x=4-√15+4+√15=8

hope it helps