for ( ) ;

f or (;) ;

for ( , );

for ( ; ; ) ;

when one wants to reduce the execution time

when there is a loop with a function call inside

when a function is called in many places in a program

both when one wants to reduce the execution time and when there is a loop with a function call inside

Sum:=N+Sum(N)

Sum:=N+Sum(N-1)

Sum:=(N-1)+Sum(N+1)

Sum:=(N-1)+Sum(N-1)

Non-recursive call

Recursive function call

Use of more external variable

None of these

Carnot ′s function

Rickmaan function

Both (a) and (b)

Ackermann ′s function