Respuesta :
[tex]\boxed{\text{De Moivre's Theorem: } (cos\theta + isin\theta )^{n} = cosn\theta + isin(n\theta )}[/tex]
[tex](cos\frac{3\pi}{12} + isin\frac{3\pi}{12})^{5} = cos\frac{5 \cdot 3\pi}{12} + isin\frac{5 \cdot 3\pi}{12}[/tex]
[tex] = cos\frac{15\pi}{12} + isin\frac{15\pi}{12} \text{ or (A)}[/tex]
[tex](cos\frac{3\pi}{12} + isin\frac{3\pi}{12})^{5} = cos\frac{5 \cdot 3\pi}{12} + isin\frac{5 \cdot 3\pi}{12}[/tex]
[tex] = cos\frac{15\pi}{12} + isin\frac{15\pi}{12} \text{ or (A)}[/tex]
(cos (3π/12) + i sin (3π/12))⁵ = (cos (15π/12) + i sin (15π/12))
Further explanation
There are many types of numbers in mathematics such as :
- Natural Numbers : 1 , 2 , 3 , 4 , 5 , . . .
- Whole Numbers : 0 , 1 , 2 , 3 , 5 , . . .
- Integers : . . . , - 3 , - 2 , - 1 , 0 , 1 , 2 , 3 , 4 , . . .
- etc
Complex Number consist of Real Number and Imaginary Number and can be expressed as :
[tex]Z = a + b ~ i[/tex]
The absolute value of complex number is also called Modulus and can be calculated using this formula :
[tex]|Z| = \sqrt { a^2 + b^2 }[/tex]
Let us tackle the problem.
De Moivre's formula for complex numbers is as follows :
[tex]\large {\boxed {[r( \cos \theta + i\sin \theta)]^n = r^n(\cos n\theta + i\sin n\theta)} }[/tex]
Using the formula above, we can solve the problem in the following way
[tex][\cos (\frac{3 \pi}{12}) + i\sin (\frac{3 \pi}{12})]^5 = \cos (5 \times \frac{3 \pi}{12}) + i\sin (5 \times \frac{3 \pi}{12})[/tex]
[tex]\large {\boxed {[\cos (\frac{3 \pi}{12}) + i\sin (\frac{3 \pi}{12})]^5 = \cos (\frac{15 \pi}{12}) + i\sin (\frac{15 \pi}{12})}}[/tex]
Learn more
- Complex Numbers : https://brainly.com/question/5056377
- Match Each Product of Complex Numbers : https://brainly.com/question/1514840
- Graph of The Complex Plane : https://brainly.com/question/10662770
Answer details
Grade: High School
Subject: Mathematics
Chapter: Complex Numbers
Keywords: Complex , Number , Real , Imaginary , Whole , Natural , Integers
