text: // problem 6
  // make sure "integral.c" file is in the same directory
  #include<stdio.h>
  #include<math.h>
  #include"integral.c"
  #define pi 3.1415927
  
  double f(double theta,double z){
      return cos(z*cos(theta))*pow(sin(theta),5);
  }
  double J2(double z){
      return pow(z,2)/(pow(2,3)*factorial(2))*simpson13(f,z,0,pi);
  }
  
  int main()
  {
    float a=0,b=10;	// range of roots
    printf("USING BISECTION METHOD\n");
    bisection(J2,a,b);   // using bisection function
    printf("\nUSING SECANT METHOD\n");
    secant(J2,a,b);   // using secant function
  }