5.
已知数列\(\{a_{n}\}\)满足\(a_{1}=1\),\(a_{n+1}=a_{n}+ \dfrac {c}{a_{n}}(c > 0,n∈N*)\),
\((\)Ⅰ\()\)证明:\(a_{n+1} > a_{n}\geqslant 1\);
\((\)Ⅱ\()\)若对任意\(n∈N*\),都有\(a_{n}\geqslant (c- \dfrac {1}{2})n-1\)
证明:\((ⅰ)\)对于任意\(m∈N*\),当\(n\geqslant m\)时,\(a_{n}\leqslant \dfrac {c}{a_{m}}(n-m)+a_{m}\)
\((ⅱ)a_{n}\leqslant \dfrac { \sqrt {5n-1}}{2}\).