curve fitting - 2nd degree polynomial (own)

#include<stdio.h>
#include<math.h>

double listX[100],listY[100];
double sumOfSquare[100];
double sumOfCube[100];
double sumOfPower4[100];
double sumOfYX[100];
double sumOfYXsquare[100];
double matrix[100][100];
double a[100];

int totatlData;

void inputData();
void printList(double*);
double sumOfList(double*);
void makeSumOfSquareList(double*);
void makeSumOfCubeList(double*);
void makeSumOfPower4List(double*);
void makeSumOfYXList(double*,double*);
void makeSumOfYXSquareList(double*,double*);
void makematrix();
void printmatrix();
void gjm();
void polynomial();

int main(void)
{
    inputData();
    makematrix();
    printmatrix();
    gjm();
    polynomial();
    return 0;
}

void inputData()
{
    printf("How many (x,y) inputs : ");
    scanf("%d",&totatlData);
    int i;
    for(i=1; i<=totatlData; i++)
    {
        printf("Enter x%d : ",i);
        scanf("%lf",&listX[i]);
        printf("Enter y%d : ",i);
        scanf("%lf",&listY[i]);
    }
}

void printmatrix()
{
    int i,j;
    for(i=1; i<=3; i++)
    {
        for(j=1; j<=3+1; j++)
        {
            printf("%lf\t",matrix[i][j]);
        }
        printf("\n");
    }
}

void printList(double x[])
{
    int i;
    for(i=1; i<=totatlData; i++)
    {
        printf("Item %d : %lf\n",i,x[i]);
    }
    printf("\n");
}

double sumOfList(double x[])
{
    int i;
    double sum = 0;
    for(i=1; i<=totatlData; i++)
    {
        sum=sum+x[i];
    }
    return sum;
}
void makeSumOfSquareList(double x[])
{
    int i;
    for(i=1; i<=totatlData; i++)
    {
        sumOfSquare[i] = pow(x[i],2);
    }
}
void makeSumOfCubeList(double x[])
{
    int i;
    for(i=1; i<=totatlData; i++)
    {
        sumOfCube[i] = pow(x[i],3);
    }
}
void makeSumOfPower4List(double x[])
{
    int i;
    for(i=1; i<=totatlData; i++)
    {
        sumOfPower4[i] = pow(x[i],4);
    }
}
void makeSumOfYXList(double y[],double x[])
{
    int i;
    for(i=1; i<=totatlData; i++)
    {
        sumOfYX[i] = y[i]*x[i];
    }
}
void makeSumOfYXSquareList(double y[],double x[])
{
    int i;
    for(i=1; i<=totatlData; i++)
    {
        sumOfYXsquare[i] = y[i]*pow(x[i],2);
    }
}
void makematrix()
{
    makeSumOfSquareList(listX);
    makeSumOfCubeList(listX);
    makeSumOfPower4List(listX);
    makeSumOfYXList(listY,listX);
    makeSumOfYXSquareList(listY,listX);
    matrix[1][1]=totatlData;
    matrix[1][2]=sumOfList(listX);
    matrix[1][3]=sumOfList(sumOfSquare);
    matrix[1][4]=sumOfList(listY);
    matrix[2][1]=sumOfList(listX);
    matrix[2][2]=sumOfList(sumOfSquare);
    matrix[2][3]=sumOfList(sumOfCube);
    matrix[2][4]=sumOfList(sumOfYX);
    matrix[3][1]=sumOfList(sumOfSquare);
    matrix[3][2]=sumOfList(sumOfCube);
    matrix[3][3]=sumOfList(sumOfPower4);
    matrix[3][4]=sumOfList(sumOfYXsquare);
}

void gjm()
{
    //printmatrix();
    int i,j,k,n=3;
    double pivotSafe=0,pivotOwn=0;
    for(k=1; k<=n; k++)
    {
        for(i=1; i<=n; i++)
        {
            if(i!=k)
            {
                pivotSafe = matrix[k][k];
                pivotOwn = matrix[i][k];
                for(j=1; j<=n+1; j++)
                {
                    matrix[i][j]=(pivotSafe*matrix[i][j])-(pivotOwn*matrix[k][j]);
                }
            }
        }
    }
    //printmatrix();
    for(i=1; i<=n; i++)
    {
        double pivot = matrix[i][i];
        for(j=1; j<=n+1; j++)
        {
            matrix[i][j]=matrix[i][j]/pivot;
        }
    }
    //printmatrix();
}

void polynomial()
{
    int i;
    printf("y=%lfx+%lfx+%lfx^2",matrix[1][4],matrix[2][4],matrix[3][4]);
}