Matching the following functions with the class

Prompt $1$n$($n$+1)/2$

Answer for prompt $1$ n$($n$+1)/2$

Prompt $22$n log$($n$+2)^2+($n$+2)^2$ log $($n$/2)$

Answer for prompt $22$n log$($n$+2)^2+($n$+2)^2$ log $($n$/2)$

Prompt $3($n$^2+1)^5$