# Another C++ Program

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/*Code compiled using Dev C++ from bloodshed.*/ #include <fstream> #include <iostream> #include <iomanip> using namespace std; double f(double x) //Function {double func = (0.6*x*x) + 2; return func;} int main() { double dx, a, b, n, m, dm; //Variable declarations. double lram, rram, mram, trap; lram = rram = mram = trap = 0; cout<<"Program 14. Rectangular Approximation Methods. \n\n"; char start, choice; cout<<"To start program, enter y, to end enter n: "; cin>>start; while(start=='y') { cout<<"Enter the lower limit (a), the upper limit (b) and divisions (n): "; cin>>a>>b>>n; dx = (b-a)/n; //Delta x. for(m=0; m<n; m++){//Beginning of for loop. dm = (m+1)*dx; lram = lram + dx*f(a + m*dx); //Area using left rectangular approximation formula. rram = rram + dx*f(a + dm); //Area using right rectangular approximation formula. mram = mram + dx*f(a+0.5*dx+m*dx); //Area using midpoint approximation formula. trap = trap + dx/2.0*(f(a+m*dx)+f(a+dm));} //Trapezodial approximation formula. cout<<"For a = "<<a<<", b = "<<b<<" and n = "<<n<<endl; cout<<"LRAM is = "<<lram<<endl; cout<<"MRAM is = "<<mram<<endl; cout<<"RRAM is = "<<rram<<endl; cout<<"TRAP is = "<<trap<<"\n\n"; cout<<"Would you like to continue? (y/n): "; cin>>choice; if(choice=='y'){ lram = rram = mram = trap = 0.0;} //Sets all equations to zero before loop. else return 0; } //End of while loop. if(start == 'n') //Quits program if user inputs character n at beginning. return 0; else system("PAUSE"); return 0; }