積分

package math;

import org.apache.commons.math3.analysis.UnivariateFunction;
import org.apache.commons.math3.analysis.solvers.BisectionSolver;
import org.apache.commons.math3.analysis.solvers.UnivariateSolver;

class pro{

public static void main(String[] args) {

pro test=new pro();
}

pro(){
        
UnivariateSolver sol = new BisectionSolver();      
double re = sol.solve(100, f, 10, 90);

System.out.println(re);
    
    

}

UnivariateFunction f = new UnivariateFunction() {
public double value(double x) {
return  d(x)-s(x);
}   
};

double d(double x){
double d1;
    d1=100-x;
if(d1<0)d1=0;
return d1;
}
double s(double x){
double s1;
    s1=x;
if(s1<0)s1=0;
return s1;
}

}