#include <iostream>
#include <cmath>

using namespace std;

double f (double x)
{
	return sin (x);
}

double derivative (double (*f) (double), double x)
{
	const double h = 1E-4;

	return (f (x + h) - f (x - h)) / (2 * h);
}

double integral (double (*f) (double), double a, double b)
{
	double Delta = 1E-4, output = 0;

	for (double x = a; x < b - Delta; x += Delta)
		output += Delta * (f (x) + f (x + Delta)) / 2;

	return output;
}

int main (int argc, char** argv)
{
	double x = 0;

	cout << "f (" << x << ") = " << f (x) << endl;
	cout << "f' (" << x << ") = " << derivative (&f, x) << endl;

	cout << "int (f, 0, M_PI) = " << integral (&f, 0, M_PI) << endl;

	return 0;

}