MAT2611 SEMESTER 1 ASSIGNMENT 2 2022
Problem 3
𝑀𝑒𝑡ℎ𝑜𝑑 1
1
= 𝑐 + 𝑖𝑑 𝑎 ≠ 0 𝑎𝑛𝑑 𝑏 ≠ 0 ∴ 𝑎 + 𝑖𝑏 ≠ 0
𝑎 + 𝑖𝑏
1
= (𝑐 + 𝑖𝑑)
(𝑎 + 𝑖𝑏)
1
× (𝑎 + 𝑖𝑏) = (𝑐 + 𝑖𝑑) × (𝑎 + 𝑖𝑏)
(𝑎 + 𝑖𝑏)
1 = (𝑐 + 𝑖𝑑)(𝑎 + 𝑖𝑏)
1 = 𝑐(𝑎 + 𝑖𝑏) + 𝑖𝑑(𝑎 + 𝑖𝑏)
1 = 𝑐𝑎 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑 + 𝑖 2 𝑏𝑑
1 = 𝑐𝑎 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑 + (−1)𝑏𝑑
1 = 𝑐𝑎 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑 − 𝑏𝑑
1 = 𝑐𝑎 − 𝑏𝑑 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑
1 + 0𝑖 = (𝑐𝑎 − 𝑏𝑑) + 𝑖(𝑏𝑐 + 𝑎𝑑)
𝑐𝑎 − 𝑏𝑑 = 1 (1)
𝑏𝑐 + 𝑎𝑑 = 0 (2)
𝐹𝑟𝑜𝑚 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛 (2),
𝑏𝑐 = −𝑎𝑑
𝑎𝑑
𝑐=− (𝑟𝑒𝑐𝑎𝑙𝑙 𝑡ℎ𝑎𝑡 𝑏 ≠ 0)
𝑏
Problem 3
𝑀𝑒𝑡ℎ𝑜𝑑 1
1
= 𝑐 + 𝑖𝑑 𝑎 ≠ 0 𝑎𝑛𝑑 𝑏 ≠ 0 ∴ 𝑎 + 𝑖𝑏 ≠ 0
𝑎 + 𝑖𝑏
1
= (𝑐 + 𝑖𝑑)
(𝑎 + 𝑖𝑏)
1
× (𝑎 + 𝑖𝑏) = (𝑐 + 𝑖𝑑) × (𝑎 + 𝑖𝑏)
(𝑎 + 𝑖𝑏)
1 = (𝑐 + 𝑖𝑑)(𝑎 + 𝑖𝑏)
1 = 𝑐(𝑎 + 𝑖𝑏) + 𝑖𝑑(𝑎 + 𝑖𝑏)
1 = 𝑐𝑎 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑 + 𝑖 2 𝑏𝑑
1 = 𝑐𝑎 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑 + (−1)𝑏𝑑
1 = 𝑐𝑎 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑 − 𝑏𝑑
1 = 𝑐𝑎 − 𝑏𝑑 + 𝑖𝑏𝑐 + 𝑖𝑎𝑑
1 + 0𝑖 = (𝑐𝑎 − 𝑏𝑑) + 𝑖(𝑏𝑐 + 𝑎𝑑)
𝑐𝑎 − 𝑏𝑑 = 1 (1)
𝑏𝑐 + 𝑎𝑑 = 0 (2)
𝐹𝑟𝑜𝑚 𝑒𝑞𝑢𝑎𝑡𝑖𝑜𝑛 (2),
𝑏𝑐 = −𝑎𝑑
𝑎𝑑
𝑐=− (𝑟𝑒𝑐𝑎𝑙𝑙 𝑡ℎ𝑎𝑡 𝑏 ≠ 0)
𝑏