float gety(float x,float y){
float y1,f1,f2;
f1= x*x + x*y - 10 ;
f2= y + 3*x*y*y - 57;
y1=df2x(y)*f1-df1x(x,y)*f2;
return(y1/detJ(x,y));
}
float gety(float x,float y) {
float y1,f1,f2;
f1=x*x+x*y;
f2=y+3*x*y*y;
y1=-df2x(x,y)*f1+df1x(x,y)*f2;
return(y1/detJ(x,y));
}
int main(void){
float x, y, error, max;
float a, b, dx, dy, jac;
printf("Enter initial approximation for x and y:\n");
scanf("%f %f", &x, &y);
do{
printf("x: %f;\t dx: %f;\ny: %f;\t dy: %f\n\n", x, dx, y, dy);
a = f1(x,y);
b = f2(x,y);
jac = jacobian(x,y);
dx = (b*df1y(x,y) - a*df2y(x,y))/jac;
dy = (a*df2x(x,y) - b*df1x(x,y))/jac;
x = x + dx;
y = y + dy;
printf("x: %f;\t dx: %f;\ny: %f;\t dy: %f;\n\n", x, dx, y, dy);
max = (fabs(dx) > fabs(dy))?fabs(dx):fabs(dy);
}while(max > EPSILON);
return 0;
}
float detJ(float x,float y){
float z;
z=df1x(x,y)*df2y(y,x) - df2x(y)*df1y(x);;
return(z);
}
float jacobian(float x, float y){
return (df1x(x,y)*df2y(x,y) - df1y(x,y)*df2x(x,y));
}