Bepaal modulus en argument

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Bepaal modulus en argument

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

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Bepaal modulus en argument

Verbetersleutel

1. \(4-4i\\ r = \sqrt{4^2+(-4)^2} = \sqrt{32} \\ \alpha = tan^{-1}(\frac{-4}{4}) \Leftrightarrow \alpha =135^\circ \text{ of } \alpha = 315^\circ \\4-4i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 315^\circ \)
2. \(9-5i\\ r = \sqrt{9^2+(-5)^2} = \sqrt{106} \\ \alpha = tan^{-1}(\frac{-5}{9}) \Leftrightarrow \alpha =150^\circ 56' 43{,}4"\text{ of } \alpha = 330^\circ 56' 43{,}4"\\9-5i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 330^\circ 56' 43{,}4"\)
3. \(9\\ \text{ Dit complex getal ligt op het positief gedeelte van de x-as. We hebben geen berekeningen nodig om r of } \alpha \text{ te berekenen.} \\\text{r = }9\\\alpha = 0 ^\circ \\\)
4. \(-2+9i\\ r = \sqrt{(-2)^2+9^2} = \sqrt{85} \\ \alpha = tan^{-1}(\frac{9}{-2}) \Leftrightarrow \alpha =102^\circ 31' 43{,}7"\text{ of } \alpha = 282^\circ 31' 43{,}7"\\-2+9i\text{ ligt in kwadrant }2, \alpha \text{ ligt dus tussen }90^\circ \text{ en }180^\circ\\ \alpha = 102^\circ 31' 43{,}7"\)
5. \(5-6i\\ r = \sqrt{5^2+(-6)^2} = \sqrt{61} \\ \alpha = tan^{-1}(\frac{-6}{5}) \Leftrightarrow \alpha =129^\circ 48' 20{,}1"\text{ of } \alpha = 309^\circ 48' 20{,}1"\\5-6i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 309^\circ 48' 20{,}1"\)
6. \(10-5i\\ r = \sqrt{10^2+(-5)^2} = \sqrt{125} \\ \alpha = tan^{-1}(\frac{-5}{10}) \Leftrightarrow \alpha =153^\circ 26' 5{,}8"\text{ of } \alpha = 333^\circ 26' 5{,}8"\\10-5i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 333^\circ 26' 5{,}8"\)
7. \(-8-8i\\ r = \sqrt{(-8)^2+(-8)^2} = \sqrt{128} \\ \alpha = tan^{-1}(\frac{-8}{-8}) \Leftrightarrow \alpha =45^\circ \text{ of } \alpha = 225^\circ \\-8-8i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 225^\circ \)
8. \(8-8i\\ r = \sqrt{8^2+(-8)^2} = \sqrt{128} \\ \alpha = tan^{-1}(\frac{-8}{8}) \Leftrightarrow \alpha =135^\circ \text{ of } \alpha = 315^\circ \\8-8i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 315^\circ \)
9. \(-7-8i\\ r = \sqrt{(-7)^2+(-8)^2} = \sqrt{113} \\ \alpha = tan^{-1}(\frac{-8}{-7}) \Leftrightarrow \alpha =48^\circ 48' 50{,}7"\text{ of } \alpha = 228^\circ 48' 50{,}7"\\-7-8i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 228^\circ 48' 50{,}7"\)
10. \(7-3i\\ r = \sqrt{7^2+(-3)^2} = \sqrt{58} \\ \alpha = tan^{-1}(\frac{-3}{7}) \Leftrightarrow \alpha =156^\circ 48' 5{,}1"\text{ of } \alpha = 336^\circ 48' 5{,}1"\\7-3i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 336^\circ 48' 5{,}1"\)
11. \(4-2i\\ r = \sqrt{4^2+(-2)^2} = \sqrt{20} \\ \alpha = tan^{-1}(\frac{-2}{4}) \Leftrightarrow \alpha =153^\circ 26' 5{,}8"\text{ of } \alpha = 333^\circ 26' 5{,}8"\\4-2i\text{ ligt in kwadrant }4, \alpha \text{ ligt dus tussen }270^\circ \text{ en }360^\circ\\ \alpha = 333^\circ 26' 5{,}8"\)
12. \(-9-3i\\ r = \sqrt{(-9)^2+(-3)^2} = \sqrt{90} \\ \alpha = tan^{-1}(\frac{-3}{-9}) \Leftrightarrow \alpha =18^\circ 26' 5{,}8"\text{ of } \alpha = 198^\circ 26' 5{,}8"\\-9-3i\text{ ligt in kwadrant }3, \alpha \text{ ligt dus tussen }180^\circ \text{ en }270^\circ\\ \alpha = 198^\circ 26' 5{,}8"\)