A friend showed me this and neither of us can work out a proof.

lim n→∞((sqroot(n+2)-sqroot(n+1))/(sqroot(n+1)-sqroot(n)))

I know the limit is 1 but I'm just looking for a method to prove it. So not putting in high values and seeing what it tends to and doing it by inspection probably wouldn't be ideal. I've tried multiplying the numerator and denominator by several values such as sqroot(n+1)/sqroot(n+1) and hit dead ends with all of them so I'm assuming there's a different approach I'm not seeing. Thanks for any help in advance =)