$1$ Asymptotic Notations

$1\mathrm{.}1$ Problem $1[15$ pts$]$

Problem $1.$ Show the following:

$10($n $+1)2=\backslash$Theta $($n$2)$

$1000$logn $=$ O$($n$)$

$1020=\backslash$Theta $(1)$

Proof.