Bug introduced in 9.0 and fixed in 10.0.0 and reintroduced in 11.2
Mathematica 9 on Windows and WolframAlpha says
Limit[Sin[Sqrt[x+1]]-Sin[Sqrt[x]],x->Infinity]
is Interval[{-2,2}]. But actually the limit is 0.
Limit[TrigFactor[Sin[Sqrt[x+1]]-Sin[Sqrt[x]]],x->Infinity]
gives 0 correctly.
Interval[{-2, 2}]
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