Cho hình chóp S. ABCD có đáy ABCD là hình thang vuông tại 2 đỉnh A, D. Tam giác SAB vuông cân tại A. Biết AB=3a, AD=a, CD=2a. Điểm M di động trên AD, mặt phẳng (P) đi qua M song song SA, CD. Mặt phẳng B cắt SD, SC, BC tại F, E, N. Gọi I là giao điểm của ME và FN, J là trung điểm BC, Q là giao điềm của IJ với mặt phẳng (SAB). Chứng minh SQ đi qua trung điểm AB và

Find the exact value of each of the following. in each case, show your work and explain the steps you take to find the value. (a) sin 17π/6 (b) tan 13π/4 (c) sec 11π/3

Aweekly newspaper charges $72 for each inch in length and one column width. what is the cost of an ad that runs 2 column inches long and 2 columns wide? its not 288

In a study of the relationship between socio-economic class and unethical behavior, 129 university of california undergraduates at berkeley were asked to identify themselves as having low or high social-class by comparing themselves to others with the most (least) money, most (least) education, and most (least) respected jobs. they were also presented with a jar of individually wrapped candies and informed that the candies were for children in a nearby laboratory, but that they could take some if they wanted. after completing some unrelated tasks, participants reported the number of candies they had taken. it was found that those who were identiď¬ed as upper-class took more candy than others. in this study, identify: (a) the cases, (b) the variables and their types, (c) the main research question, (d) identify the population of interest and the sample in this study, and (e) comment on whether or not the results of the study can be generalized to the population, and if the ď¬ndings of the study can be used to establish causal relationships.