Can you explain the integration in depth? I'm not understanding the integration part to find the exact area.

Find the approximate area under the curve by dividing the intervals into n subintervals and then adding up the areas of the inscribed rectangles. The height of each rectangle may be found by evaluating the function for each value of x. The n value is the number of rectangles used in the approximation. n =10 and n = 4. . y = 2x \\ x- + 1 between x = 0 and x = 6 for n and n2 . Find the exact area under the curve using integration y = 2xx + 1 between x = 0 and x = 6 Can you explain the difference between the answers