EXCEL, 26 Bytes pajonk

=SQRT(A1)*A1^2/1/ISNA(IP2) 

A1 as input IP2 contain a second input with a #N/A Error in this case ISNA(IP2) belongs to 1

For an additional () we can do this

=SQRT(A1)*A1^2/ISNA(PI(1/2)) 

EXCEL, 26 Bytes pajonk

=SQRT(A1)*A1^2/1/ISNA(IP2) 

A1 as input IP2 contain a second input with a #N/A Error in this case ISNA(IP2) belongs to 1

For an additional () we can do this

=SQRT(A1)*A1^2/ISNA(PI(1/2)) 

EXCEL, 26 Bytes pajonk

=SQRT(A1)*A1^2/1/ISNA(IP2) 

A1 as input IP2 contain a second input with a #N/A Error in this case ISNA(IP2) belongs to 1

For an additional `()´ we can do this

=SQRT(A1)*A1^2/ISNA(PI(1/2)) 

EXCEL, 26 Bytes pajonk

=SQRT(A1)*A1^2/1/ISNA(IP2) 

A1 as input IP2 contain a second input with a #N/A Error in this case ISNA(IP2) belongs to 1

For an additional () we can do this

=SQRT(A1)*A1^2/ISNA(PI(1/2)) 

EXCEL, 26 Bytes pajonk

=SQRT(A1)*A1^2/1/ISNA(IP2) 

A1 as input IP2 contain a second input with a #N/A Error in this case ISNA(IP2) belongs to 1

EXCEL, 26 Bytes pajonk

=SQRT(A1)*A1^2/1/ISNA(IP2) 

A1 as input IP2 contain a second input with a #N/A Error in this case ISNA(IP2) belongs to 1

For an additional `()´ we can do this

=SQRT(A1)*A1^2/ISNA(PI(1/2))