4th edition - IGCSE_RimPimentel_Hodder Textbook answers with working

Let f (x) = x e8x. find a formula for the nth derivative of f, where n is any positive integer. use x and n in your answer if needed. f (n)(x) =

Determine whether the points (–3,–6) and (2,–8) are in the solution set of the system of inequalities below. x ? –3 y < 5? 3x + 2 a. the point (–3,–6) is not in the solution set, and the point (2,–8) is in the solution set. b. neither of the points is in the solution set. c. the point (–3,–6) is in the solution set, and the point (2,–8) is not in the solution set. d. both points are in the solution set.

Do social recommendations increase ad effectiveness? a study of online video viewers compared viewers who arrived at an advertising video for a particular brand by following a social media recommendation link to viewers who arrived at the same video by web browsing. data were collected on whether the viewer could correctly recall the brand being advertised after seeing the video. the results are given below.correctly recalled the brandarrival 409153browsing20484b. conduct the hypothesis test, using the 0.025 level of significance.what is the value of the test statistic? χ2stat=what is the p-value? p-value=is this value significant atα=0.025?