Write implementation of function serie()

Question

I am solving some programming issues, but I am struggling with this issue, if anyone can help me I will be very grateful.

The question and the following.

Write the implementation of the function serie() declared in the prototype, according to the equation:

#include    <stdio.h>   
float   serie(int   num);   
main()  
{   
int n;  
printf(“Informe a   quantidade  de  termos  (>=1):  “); 
scanf(“%d”, &n);    
if  (n<1)   
printf(“Valor   incorreto!”);   
else    
printf(“O   resultado   da  série   é   %f  \n”,    serie(n));  
}

In advance I appreciate the support!