35. anyone know calc.?

Question

in a marathong when the winner crosses the finish line many runners are still on the course some quite far behind if the density of runners x miles from the finish line is given by R9x) = 20[1-cos(1 + 0.03x^2)] runners per mile how many within 8 miles of the finish line

Answer 1

Just integrate that function with respect to x and evaluate at 0 and 8 miles.