Function to return a pointer to the largest number in an array

as you can tell by the title I need to write a function that returns a pointer to the largest number in an array, the functions gets a pointer to a double array and it's size. In addition I need to write a main function that will use this function. Here is the code that I wrote:

#include <stdio.h>
#include <stdlib.h>
void BigEl(double* arr, double arrSize);

void BigEl(double* arr, double arrSize)
{
    int i;
    double  maximum, *x;
    maximum = arr[0];
    for (i = 1; i < arrSize; i++)
    {
        if (arr[i]>maximum)
        {
            maximum = arr[i];
        }
    }
    *x = maximum;
}
void main()
{
    double myarr[10];
    int i;
    printf("Please insert 10 numbers to the array\n");
    for (i = 0; i < 10; i++)
    {
        scanf("%d", &myarr[i]);
    }
    BigEl(myarr, 10);


}

I get this error:

Error   1   error C4700: uninitialized local variable 'x' used

I don't understand what I did wrong because I did initialized x. Any kind of help is appreciated, in addition, tell me if the idea of my code was right because Im not sure if I understood the question correctly.