Question 19 1 pts 2x Choose a u-substitution and rewrite the integral in terms of u: dx 9-25x- O 1 du 25 Ju 0 -100 du Ju O du UTIN 19 - uz 10 du 19 - uz More than one of the above substitutions is correct O None of these substitutions are correctQuestion 18 3 Which of the following are equivalent to dx ? 7x2 +9 Select all that apply. 0 317 du 42 + 9 O 3 du u2 + 9 V 1 tan V 7tan - 1 ( V7x + c None of theseQuestion 26 Find all the points at which the tangent line to the curve is vertical? Select all that apply. X = cos(30) y = 3sine O 1 , 3V/3 2 -1, 3V3 2 313 2 V -1, 3V/3 2 O (1, 0) O (-1, 0) The tangent line is not vertical at any of these points