Minimum of two floating-point numbers

I’m learning C and I just had the exercise to write a function that checks for the lower one of two floating-points.
So I thought, I either could use pointer and also return the pointer of the lower value – otherwise, I simply could use the values and return the lower value.

double* pointer_min_value(double* first, double* second){
    return *first > *second ? second : first;

double calc_min_value(double first, double second){
    return first > second ? second : first;

int main() {
    printf("Enter two numbers to define the minimum!n");

    double first, second;
    scanf("%lf%lf", &first, &second);

    printf("The lower value is %lf", *pointer_min_value(&first, &second));
    printf("The lower value is %lf", calc_min_value(first, second));

    return 0;

they both work, but what would make more sense? should I use pointer only if I want to change the value (I mean, I should not change any of the parameters in a "get me the lowest number"-funtion), or would it be better in any other view (resources, performance,…).