Grade 12 Maths
Grade 12 Maths
Grade 12 Maths
Choose the correct or the most appropriate answer of each question. Write the letter of the correct
1. 𝐼𝑓 𝑧 = 3 + 4𝑖 , 𝑡ℎ𝑒𝑛 𝑧𝑧̅ =
𝐴. −25𝑖 𝐵. 25 𝐶. −25 𝐷. 25𝑖
2. 𝑀𝑜𝑑𝑢𝑙𝑢𝑠 𝑜𝑓 𝑧 𝑖𝑠
𝑧̅
𝐴. √𝑧 𝐵. √𝑧̅ 𝐶. √𝑧𝑧̅ 𝐷. √ .
𝑧
Write only the solution of each question. (There is no need to show your working)
̅̅̅̅̅̅̅
2+3𝑖
11. 𝑆𝑖𝑚𝑝𝑙𝑖𝑓𝑦 .
−4−5𝑖
12. 𝑇ℎ𝑒 𝑐𝑜𝑟𝑟𝑑𝑖𝑛𝑎𝑡𝑒 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑜𝑖𝑛𝑡𝑠 𝐴 𝑎𝑛𝑑 𝐵 𝑎𝑟𝑒 (−1,3,14) 𝑎𝑛𝑑 (2𝑘, 3𝑘, 13). 𝐺𝑖𝑣𝑒𝑛 𝑡ℎ𝑎𝑡 𝑡ℎ𝑒 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 𝑓𝑟𝑜𝑚 𝐴 𝑡𝑜 𝐵 𝑖𝑠
2 −1
20. 𝐹𝑖𝑛𝑑 𝑡ℎ𝑒 𝑎𝑛𝑔𝑙𝑒 𝑏𝑒𝑡𝑤𝑒𝑒𝑛 (−1) 𝑎𝑛𝑑 ( 3 )
−1 2
̅̅̅̅̅
𝑧 𝑧
̅̅̅
22. 𝐿𝑒𝑡 𝑧1 = 3 − 2𝑖 , 𝑧2 = −1 + 4𝑖 , 𝑠ℎ𝑜𝑤 𝑡ℎ𝑎𝑡 ( 1) = 1.
𝑧2 𝑧2
23. 𝐹𝑖𝑛𝑑 𝑡ℎ𝑒 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑝𝑙𝑎𝑛𝑒 𝑐𝑜𝑛𝑡𝑎𝑖𝑛𝑖𝑛𝑔 𝐴(4,2, −3), 𝐵(1, −2,4), 𝐶(−1,0,3).
24. 𝑆ℎ𝑜𝑤 𝑡ℎ𝑎𝑡 𝑡ℎ𝑒 𝑝𝑜𝑖𝑛𝑡𝑠 (1, −1,2), (3, −2,3) 𝑎𝑛𝑑 (5, −3,4)𝑎𝑟𝑒 𝑐𝑜𝑙𝑙𝑖𝑛𝑒𝑎𝑟.
25. 𝑇ℎ𝑒𝑟𝑒 𝑎𝑟𝑒 5 𝑝𝑖𝑐𝑡𝑢𝑟𝑒 𝑛𝑎𝑖𝑙𝑠 𝑜𝑛 𝑡ℎ𝑒 𝑤𝑎𝑙𝑙. 𝐼𝑓 𝑡ℎ𝑒𝑟𝑒 𝑎𝑟𝑒 8 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑡 𝑝𝑖𝑐𝑡𝑢𝑟𝑒𝑠 𝑎𝑛𝑑 𝑒𝑎𝑐ℎ 𝑛𝑎𝑖𝑙 𝑐𝑎𝑛 ℎ𝑜𝑙𝑑 𝑜𝑛𝑙𝑦 𝑜𝑛𝑒
𝑝𝑖𝑐𝑡𝑢𝑟𝑒, 𝑖𝑛 ℎ𝑜𝑤 𝑚𝑎𝑛𝑦 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑡 𝑤𝑎𝑦𝑠 𝑐𝑎𝑛 𝑡ℎ𝑒 𝑝𝑖𝑐𝑡𝑢𝑟𝑒𝑠 𝑏𝑒 ℎ𝑢𝑛𝑔 𝑜𝑛 𝑎𝑙𝑙 𝑡ℎ𝑒 𝑛𝑎𝑖𝑙𝑠.
26. 𝐼𝑓 𝑎 𝑝ℎ𝑜𝑛𝑒 𝑘𝑒𝑦𝑝𝑎𝑑 ℎ𝑎𝑠 6 𝑑𝑖𝑔𝑖𝑡 𝑝𝑎𝑠𝑠𝑤𝑜𝑟𝑑, 𝑐𝑜𝑛𝑡𝑎𝑖𝑛𝑖𝑛𝑔 0,1,2,3,4,5 𝑎𝑛𝑑 𝑡ℎ𝑒 𝑐𝑜𝑑𝑒 𝑡𝑜 𝑜𝑝𝑒𝑛 𝑡ℎ𝑒 𝑠𝑐𝑟𝑒𝑒𝑛 𝑚𝑢𝑠𝑡 𝑏𝑒 𝑎
4 𝑑𝑖𝑔𝑖𝑡 𝑐𝑜𝑑𝑒 , ℎ𝑜𝑤 𝑚𝑎𝑛𝑦 𝑐𝑜𝑑𝑒𝑠 𝑎𝑟𝑒 𝑝𝑜𝑠𝑠𝑖𝑏𝑙𝑒 𝑡𝑜 𝑐𝑟𝑒𝑎𝑡𝑒 𝑖𝑓 𝑡ℎ𝑒 𝑟𝑒𝑝𝑒𝑡𝑖𝑡𝑖𝑜𝑛 𝑖𝑠 𝑎𝑙𝑙𝑜𝑤𝑒𝑑?
28. 𝑆ℎ𝑜𝑤 𝑏𝑦 𝑖𝑛𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑡ℎ𝑎𝑡 3𝑛 − 1 𝑖𝑠 𝑎𝑛 𝑒𝑣𝑒𝑛 𝑛𝑢𝑚𝑏𝑒𝑟 𝑓𝑜𝑟 𝑎𝑙𝑙 𝑛𝑎𝑡𝑢𝑟𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 𝑛.
3𝑛−1
29. 𝑈𝑠𝑒 𝑡ℎ𝑒 𝑚𝑎𝑡ℎ𝑒𝑚𝑎𝑡𝑖𝑐𝑎𝑙 𝑖𝑛𝑑𝑢𝑐𝑡𝑖𝑜𝑛 𝑝𝑟𝑖𝑛𝑐𝑖𝑝𝑙𝑒 𝑡𝑜 𝑝𝑟𝑜𝑣𝑒 𝑡ℎ𝑎𝑡 1 + 3 + 32 + ⋯ … + 3𝑛−1 = .
2
33. 𝐹𝑖𝑛𝑑 𝑡ℎ𝑒 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑙𝑖𝑛𝑒 𝑝𝑎𝑠𝑠𝑖𝑛𝑔 𝑡ℎ𝑟𝑜𝑢𝑔ℎ 𝑡ℎ𝑒 𝑝𝑜𝑖𝑛𝑡 (3, −2, −2)𝑎𝑛𝑑 𝑝𝑒𝑟𝑝𝑒𝑛𝑑𝑖𝑐𝑢𝑙𝑎𝑟 𝑡𝑜 𝑡ℎ𝑒 𝑝𝑙𝑎𝑛𝑒
−2𝑥 + 3𝑦 − 𝑧 = 4. 𝐹𝑖𝑛𝑑 𝑡ℎ𝑒 𝑝𝑜𝑖𝑛𝑡 𝑜𝑓 𝑖𝑛𝑡𝑒𝑟𝑠𝑒𝑐𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑙𝑖𝑛𝑒 𝑎𝑛𝑑 𝑡ℎ𝑒 𝑝𝑙𝑎𝑛𝑒.
Saya Soe Moe Aung ( Education Center)
35. 𝐹𝑖𝑛𝑑 𝑡ℎ𝑒 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛 𝑜𝑓 𝑡ℎ𝑒 𝑠𝑝ℎ𝑒𝑟𝑒 𝑤𝑖𝑡ℎ 𝑐𝑒𝑛𝑡𝑒𝑟 (6, −7, −3) 𝑎𝑛𝑑 𝑡𝑜𝑢𝑐ℎ𝑖𝑛𝑔 𝑡ℎ𝑒 𝑝𝑙𝑎𝑛𝑒 4𝑥 − 2𝑦 − 𝑧 = 17.
36. 𝐴 𝑟𝑒𝑔𝑠𝑖𝑡𝑟𝑎𝑡𝑖𝑜𝑛 𝑐𝑜𝑑𝑒 𝑐𝑜𝑛𝑠𝑡𝑖𝑡𝑠 𝑜𝑓 𝑡𝑤𝑜 𝑜𝑓 𝑡ℎ𝑒 15 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑡 𝑐𝑎𝑝𝑖𝑡𝑎𝑙 𝑙𝑒𝑡𝑡𝑒𝑟𝑠 𝐴, 𝐵, 𝐶, … … ,0, 𝑓𝑜𝑙𝑙𝑜𝑤𝑒𝑑 𝑏𝑦 𝑜𝑛𝑒
𝑜𝑓 𝑡ℎ𝑒 𝑡𝑒𝑛 𝑑𝑖𝑔𝑖𝑡𝑠 0,1,2, … … ,9 𝑓𝑜𝑟 𝑒𝑥𝑎𝑚𝑝𝑙𝑒 𝐼𝐷5. 𝐻𝑜𝑤 𝑚𝑎𝑛𝑦 𝑐𝑜𝑑𝑒𝑠 𝑎𝑟𝑒 𝑝𝑜𝑠𝑠𝑖𝑏𝑙𝑒 𝑡𝑜 𝑔𝑒𝑛𝑒𝑟𝑎𝑡𝑒.
(𝑑) 𝑖𝑓 𝑡𝑤𝑜 𝑙𝑒𝑡𝑡𝑒𝑟𝑠 𝑎𝑟𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑡, 𝑏𝑢𝑡 𝑚𝑢𝑠𝑡 𝑏𝑒 𝑏𝑜𝑡ℎ 𝑣𝑜𝑤𝑒𝑙𝑠 𝑜𝑟 𝑏𝑜𝑡ℎ 𝑐𝑜𝑛𝑠𝑜𝑛𝑎𝑛𝑡𝑠.
(2𝑛−1)3𝑛+1 +3
37. 𝑃𝑟𝑜𝑣𝑒 𝑡ℎ𝑎𝑡 1.3 + 2. 32 + 3. 33 +. . . +𝑛. 3𝑛 = 𝑓𝑜𝑟 𝑎𝑙𝑙 𝑛𝑎𝑡𝑢𝑟𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟𝑠 𝑛 𝑏𝑦 𝑡ℎ𝑒 𝑢𝑠𝑒 𝑜𝑓 𝑡ℎ𝑒
4
𝑚𝑎𝑡ℎ𝑒𝑚𝑎𝑡𝑖𝑐𝑎𝑙 𝑖𝑛𝑑𝑢𝑐𝑡𝑖𝑜𝑛.