Pointers in C Programming- Coordinate conversion -

i should write program convert cartesian coordinates polar , vice versa use of pointers, wrote following code function gives me segmentation fault. tried without pointers , still doesn't send numbers function, can modify pointer code? i'm new c.

#include <stdio.h> #include <math.h>  void cart(float *radius,float *degree) {     float *x,*y,*radians;     *radians= (3.14159265359/180) * *degree;     *x= *radius * cos(*radians);      *y= *radius * sin(*radians); }  int main() {     float radius, radians, degree;     float x,y;     int m;     char c,p;     printf(" enter c if converting cartesian polar \n");      printf(" enter p if converting polar cartesian \n");     scanf("%c",&m);      if (m=='p')     {         printf("enter radius , angle separated comma \n");         scanf("%f,%f",&radius,&degree);         cart(&radius,&degree);         printf("cartesian form (%f,%f) \n",x,y);     }     else if (m=='c')     {         printf("enter values of x , y separated comma \n");         scanf("%f,%f",&x,&y);         radius=sqrt(((x*x)+(y*y))); // finding radius          radians=atan(y/x); //finding angle in radians         printf("polar form (%f,%f) \n",radius,radians); //angle in radians     }      return 0; } 

the first thing note in 'cart' function:

void cart(float *radius,float *degree) { float *x,*y,*radians; *radians= (3.14159265359/180) * *degree; *x= *radius * cos(*radians);  *y= *radius * sin(*radians); } 

you have declared pointers named x, y , radians, not yet point anything.

so when 'de-reference' them *x, *y , *radians accessing memory not exist, result in undefined behavior, possibly segmentation fault.

i assume goal x, y , radians main function match those, should passing them function well.