Computer Science Time complexity

Java

$($a$)(2$ points$)$ For each of the following statements, indicate whether the statement is true or false.

$1.$ Algorithm A is O$($log n$)$

$2.$ Algoirthm A is O$($n$2)$

$3.$ Algoirthm A is O$($n$3)$

$4.$ Algoirthm A is O$(2$n$)$

$($b$)(1$ point$)$ Can the time complexity of this algorithm be expressed using big$-\backslash$Theta notation? If so$,$ what is it$?$

T$\_($A$)($n$)=(1)/(280)$n$^(2)+42$logn$+12$n$^(3)+280\backslash$sqrt$($n$)$