Bepaal modulus en argument

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Bepaal modulus en argument

1. \(-9-8i\)
2. \(7i\)
3. \(2+9i\)
4. \(-3+7i\)
5. \(-6-7i\)
6. \(10-10i\)
7. \(-5-6i\)
8. \(-5-3i\)
9. \(5+6i\)
10. \(4+7i\)
11. \(9-8i\)
12. \(8+i\)

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Bepaal modulus en argument

Verbetersleutel

1. \(-9-8i\\ r = \sqrt{(-9)^2+(-8)^2} = \sqrt{145} \\ \alpha = tan^{-1}(\frac{-8}{-9}) \Leftrightarrow \alpha =41^\circ 38' 0{,}7"\text{ of } \alpha = 221^\circ 38' 0{,}7"\\-9-8i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 221^\circ 38' 0{,}7"\)
2. \(7i\\ \text{ Dit complex getal ligt op het positief gedeelte van de y-as. We hebben geen berekeningen nodig om r of } \alpha \text{ te berekenen.} \\\text{r = }7\\\alpha = 90 ^\circ \\\)
3. \(2+9i\\ r = \sqrt{2^2+9^2} = \sqrt{85} \\ \alpha = tan^{-1}(\frac{9}{2}) \Leftrightarrow \alpha =77^\circ 28' 16{,}3"\text{ of } \alpha = 257^\circ 28' 16{,}3"\\2+9i\text{ ligt in kwadrant }1, \alpha \text{ ligt dus tussen }0^\circ \text{ en }90^\circ\\ \alpha = 77^\circ 28' 16{,}3"\)
4. \(-3+7i\\ r = \sqrt{(-3)^2+7^2} = \sqrt{58} \\ \alpha = tan^{-1}(\frac{7}{-3}) \Leftrightarrow \alpha =113^\circ 11' 54{,}9"\text{ of } \alpha = 293^\circ 11' 54{,}9"\\-3+7i\text{ ligt in kwadrant }2, \alpha \text{ ligt dus tussen }90^\circ \text{ en }180^\circ\\ \alpha = 113^\circ 11' 54{,}9"\)
5. \(-6-7i\\ r = \sqrt{(-6)^2+(-7)^2} = \sqrt{85} \\ \alpha = tan^{-1}(\frac{-7}{-6}) \Leftrightarrow \alpha =49^\circ 23' 55{,}3"\text{ of } \alpha = 229^\circ 23' 55{,}3"\\-6-7i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 229^\circ 23' 55{,}3"\)
6. \(10-10i\\ r = \sqrt{10^2+(-10)^2} = \sqrt{200} \\ \alpha = tan^{-1}(\frac{-10}{10}) \Leftrightarrow \alpha =135^\circ \text{ of } \alpha = 315^\circ \\10-10i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 315^\circ \)
7. \(-5-6i\\ r = \sqrt{(-5)^2+(-6)^2} = \sqrt{61} \\ \alpha = tan^{-1}(\frac{-6}{-5}) \Leftrightarrow \alpha =50^\circ 11' 39{,}9"\text{ of } \alpha = 230^\circ 11' 39{,}9"\\-5-6i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 230^\circ 11' 39{,}9"\)
8. \(-5-3i\\ r = \sqrt{(-5)^2+(-3)^2} = \sqrt{34} \\ \alpha = tan^{-1}(\frac{-3}{-5}) \Leftrightarrow \alpha =30^\circ 57' 49{,}5"\text{ of } \alpha = 210^\circ 57' 49{,}5"\\-5-3i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 210^\circ 57' 49{,}5"\)
9. \(5+6i\\ r = \sqrt{5^2+6^2} = \sqrt{61} \\ \alpha = tan^{-1}(\frac{6}{5}) \Leftrightarrow \alpha =50^\circ 11' 39{,}9"\text{ of } \alpha = 230^\circ 11' 39{,}9"\\5+6i\text{ ligt in kwadrant }1, \alpha \text{ ligt dus tussen }0^\circ \text{ en }90^\circ\\ \alpha = 50^\circ 11' 39{,}9"\)
10. \(4+7i\\ r = \sqrt{4^2+7^2} = \sqrt{65} \\ \alpha = tan^{-1}(\frac{7}{4}) \Leftrightarrow \alpha =60^\circ 15' 18{,}4"\text{ of } \alpha = 240^\circ 15' 18{,}4"\\4+7i\text{ ligt in kwadrant }1, \alpha \text{ ligt dus tussen }0^\circ \text{ en }90^\circ\\ \alpha = 60^\circ 15' 18{,}4"\)
11. \(9-8i\\ r = \sqrt{9^2+(-8)^2} = \sqrt{145} \\ \alpha = tan^{-1}(\frac{-8}{9}) \Leftrightarrow \alpha =138^\circ 21' 59{,}3"\text{ of } \alpha = 318^\circ 21' 59{,}3"\\9-8i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 318^\circ 21' 59{,}3"\)
12. \(8+i\\ r = \sqrt{8^2+1^2} = \sqrt{65} \\ \alpha = tan^{-1}(\frac{1}{8}) \Leftrightarrow \alpha =7^\circ 7' 30{,}1"\text{ of } \alpha = 187^\circ 7' 30{,}1"\\8+i\text{ ligt in kwadrant }1, \alpha \text{ ligt dus tussen }0^\circ \text{ en }90^\circ\\ \alpha = 7^\circ 7' 30{,}1"\)