ai giúp cái A=1/2 ²+1/3 ²+1/4 ²+...+1/100 ² chứng minh 1/2<A<1

cos bao nhiêu số tự nhiên có 2 chữ số ko lớn hơn 2020

Giúp mình giải pt sau Cos3x = cosx

Nêu suy nghĩ của em về sự cần thiết của trân trọng cuộc sống (bài văn có mở bài,tb,kb) làm dàiiiiiii giúp e vs ạ ko đc viết ngắn ạ giúp e vs please !!

6. New evidence___________by the city attorney. A. has be discovered B. has been discovered C. are discovered D. will been discovered 7. A special committee___________the dispute. A. is going to settle B. is going to be settled C. going to settling D . will going to be settled 8. You____________by my secretary next week. A. will notify B. would notify C. will be notified D. is going to notified 9. At one time the entire world__________by dinosaurs A has ruled B. was ruled C. will be ruled D. was ruling 10. Mark_______ a lot by his friends, isn't he? A. is influenced B. is influencing C. isn't influenced D. isn’t influencing 11. A few days ago, Tom's car_________ by one of the teenagers in his neighborhood. A. was stealing B. was stole C. has been stolen D. was stolen 12. The wheel__________ thousands of years ago. A. invented B. was invented C. is invented D. has invented 13. I got upset when I _______ in the middle of my story. A. interrupted B. has interrupted C. was being interrupted D. was interrupted 14. Pencils________ at the test, so please bring your own. A. are provided B. will be provided C. won't be provided

1. Tìm x ∈ Q, biết: (x+2) . (x-$\frac{2}{3}$) > 0 2. So sánh: $\frac{-13}{19}$ và $\frac{19}{-23}$

Khi sắp xếp dữ liệu trong excel từ Z -> A xong, mình nhập mấy chữ số vào, sau đó mình muốn trở lại cách sắp xếp như ban đầu mình phải làm gì ạ?

although/he/be/injured/continue/play/until/match/finish

giúp mình nhé ෆ╹ .̮ ╹ෆ 13h30 mình đi học rồi ><

Bài 1: Tính a, (-0,5) mũ 3 b, (-2020) mũ 0 CÁC BN GIÚP MIK VỚI CTLHN LUÔN, VOTE 5 SAO LUÔN