Answer Happy

The rate of change r(t) (in thousands of articles per year) of the total number of research articles in a prominent journal written by researchers in the United States is shown in the following graph. Here, t is time in years (t = 0 represents the start of 1983). r 4 3 2 1 t 2 4 6 8 10 12 14 16 18 20 22 24 (a) Use both left and right Riemann sums with six subdivisions to estimate the total number of articles (in thousands) in the journal written by researchers in the United States during the 12-year period beginning at the start of 1993. (Estimate each value of r(t) to the nearest 0.25.) X thousand articles left sum right sum X thousand articles (b) Use the answers from part (a) to obtain an estimate of Ⓡ of 12² rt r(t) dt. x Interpret the result. Since r(t) is given in thousands of articles per year, we conclude that a total of about Enter a number. xarticles in the journal were written by researchers in the U.S. in the 12 -year period beginning 1993.