sum of square root function

[Dillano]

ddddd

[Bibek Subedi]

First, plz post the code using code tag given right hand side of text area to make it clear....
to display double, you have to make data type double or float .
To add the sum of square root of numbers to previous one , modify your SumN function like this

float SumN(int num) {
    float sum = 0;
    for(int i = 1; i <= num; i++){
        sum += sqrt(i);
    }
    return sum;
}

where num is the number you enter