Trên nửa đường tròn tâm O, đường kính AB, trên nửa đường tròn lấy 2 điểm D và C sao cho chúng tạo nên tứgiác ABCD. Gọi F là giao điểm AC và DB, AD và CB cắt nhau ở E; Từ F kẻFM vuông góc với AB. a) Chứng minhE, F, M thẳng hàng.
b) Tứ giác DECF, ADFM, FMBC, EDMB, ECMA nội tiếp được trong một đường tròn.

Apsychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. she randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. does this sampling plan result in a simple random sample? why or why not? no, because each group of 200 students in the sample does not have the same chance of being selected. yes, because each group of 200 students in the sample has the same chance of being selected. no, because each individual student does not have an equal chance of being selected. yes, because each individual student has the same chance of being selected.

Ateacher brought a pack of 17 batteries . each calculator uses 3 batteries . how many calculator can the teacher fill with batteries

Which function has an inverse function? a. f(x)= |x+3|/5 b. f(x)= x^5-3 c. f(x)= x^4/7+27 d. f(x)= 1/x²