18. Let f be the function defined by f (xx) = Vl=+3 Which of the following statements is true? O f is not differentiable at a = -3 O lim+ + 3 f (x) 40 O f is not continuous at c = -3 O = = -3 is a vertical asymptote of the graph of f O f is continuous and differentiable at a = -311. Using a trapezoidal approximation, with four subintervals of equal size, approximate the area between the graph of f and the x-axis on the interval [0, 8]. Graph of f 6 4 X 0 2 4 6 8 O 12 O 27 O 16 3217. After 28 days, a radioactive substance has decayed to 39.1% of its original amount. After an additional 33 days, what percent of its original amount will it have decayed to? C 14.350 C 12.928 O 9.696 O 4.098 O 13.57410. The table below gives values of a continuous function f. On the interval [-7, 1], the trapezoidal approximation for the area under the function, found with 4 intervals of equal length, is 3. What is the value of k? -7 5 - 3 -1 f ) -8 k O -9 O 19 O 10 O 1 28 14.513. Let f be a function that is continuous on the closed interval [4, 16]. Given that f (4) = 6 and f (16) = 14, which of the following statements is guaranteed by the Intermediate Value Theorem? O f (x) = 10 has at least one solution in the open interval (4, 16) O There is at least one maximum on the open interval (4, 16) O f (x) is always increasing O f (x) is linear O f (10) = 1015. Using a midpoint Riemann sum, with 4 rectangles of equal width, estimate the area between the function f (a) = 5(+2) and the x-axis on the interval (-2,2). For any intervals on which the function dips below the x-axis, count the area as negative. O A = 2.667 O A = 4.137 O A = 5.212 O A = 3.006 O A = 5.334