I'm making a Riemman sum code for a school project but I keep getting this error at line 37. The line is in the for loop after the statement "String coord2;".

String message, message2, numStr, numStr2, numStr3, numStr4, numStr5;
    double a, n, xmin, xmax, w, w2, w3, w4, w5, area, totalArea = 0, area2, totalArea2 = 0, area3, totalArea3 = 0, area4, totalArea4 = 0, area5, totalArea5 = 0, coord;

        message = "Our group was assigned the method: 'MID-POINT RIEMMAN SUMS'";
        JOptionPane.showMessageDialog (null, message);

        message2 = "Given the function f(x) = a*x^n...";
        JOptionPane.showMessageDialog (null, message2);

        numStr = JOptionPane.showInputDialog ("Enter a value for the coefficent of x, 'a': ");
          a = Double.parseDouble(numStr);

          numStr2 = JOptionPane.showInputDialog ("Enter a value for the power of x, 'n' (enter '1' if you would like no exponent): ");
          n = Double.parseDouble(numStr2);

        numStr3 = JOptionPane.showInputDialog ("Enter the x-min of the interval which you would like: ");
        xmin = Double.parseDouble(numStr3);

        numStr4 = JOptionPane.showInputDialog ("Enter the x-max of the interval which you would like: ");
        xmax = Double.parseDouble(numStr4);

        w = ((xmax - xmin)/5);
        for (double count = xmin; count <= 5; count++)
        {
            area = (w*a)*Math.pow((xmin + (count - 0.5)*w),n);
            totalArea += area;
        }
        String message3 = "The area enclosed between the given interval of the function with subintervals of 5 is: " + totalArea;
        JOptionPane.showMessageDialog (null, message3);
        coord = JOptionPane.showConfirmDialog (null, "Would you like the x and y values for the subintervals of 5?");
        if (coord == JOptionPane.YES_OPTION)
        {
            String coord2;

            for (double x = xmin; x <= xmax; x++)
            {
               coord2 = "X-value and Y-value: " + /n (xmin + (x - 0.5)*w) + "and" + 4*(xmin + (x - 0.5)*w);
            }
        }

        w2 = ((xmax - xmin)/10);
        for (double count2 = xmin; count2 <= 10; count2++)
        {
            area2 = (w2*a)*Math.pow((xmin + (count2 - 0.5)*w2),n);
            totalArea2 += area2;
        }
        String message4 = "The area enclosed between the given interval of the function with subintervals of 10 is: " + totalArea2;
        JOptionPane.showMessageDialog (null, message4);

        w3 = (xmax - xmin)/20;
        for (double count3 = xmin; count3 <= 20; count3++)
        {
            area3 = (w3*a)*Math.pow((xmin + (count3 - 0.5)*w3),n);
            totalArea3 += area3;
        }
        String message5 = "The area enclosed between the given interval of the function with subintervals of 20 is: " + totalArea3;
        JOptionPane.showMessageDialog (null, message5);

        w4 = (xmax - xmin)/10000;
        for (double count4 = xmin; count4 <= 10000; count4++)
        {
            area4 = (w4*a)*Math.pow((xmin + (count4 - 0.5)*w4),n);
            totalArea4 += area4;
        }
        String message6 = "The area enclosed between the given interval of the function with subintervals of 10,000 is: " + totalArea4;
        JOptionPane.showMessageDialog (null, message6);
    }
}

Edited 4 Years Ago by hoopd505

coord2 = "X-value and Y-value: " + /n (xmin + (x - 0.5)w) + "and" + 4(xmin + (x - 0.5)*w);

I think what you meant is "coord2 = "X-value and Y-value: \n" +(xmin + (x - 0.5)w) + "and" + 4(xmin + (x - 0.5)*w);"? your /n is not a math operation.

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