Get the information you need quickly and easily with IDNLearn.com. Our experts provide accurate and detailed responses to help you navigate any topic or issue with confidence.

Apply De Moivre's theorem to solve:

i) [tex]\((1+i)^{24}\)[/tex]


Sagot :

Certainly! Let's use De Moivre's theorem to solve [tex]\((1+i)^{24}\)[/tex].

### Step 1: Convert to Polar Form
First, we express the complex number [tex]\(1+i\)[/tex] in polar form.

1. Magnitude (r):
[tex]\[ r = |1+i| = \sqrt{1^2 + 1^2} = \sqrt{2} \][/tex]

2. Argument (θ):
[tex]\[ \theta = \tan^{-1}\left(\frac{\text{Im}(1+i)}{\text{Re}(1+i)}\right) = \tan^{-1}\left(\frac{1}{1}\right) = \frac{\pi}{4} \][/tex]

So, in polar form, [tex]\( 1+i = \sqrt{2} \left( \cos\frac{\pi}{4} + i \sin\frac{\pi}{4} \right) \)[/tex].

### Step 2: Apply De Moivre's Theorem
According to De Moivre’s theorem, [tex]\((r (\cos \theta + i \sin \theta))^n = r^n (\cos (n\theta) + i \sin (n\theta))\)[/tex].

For [tex]\((1+i)^{24}\)[/tex]:
1. Raise the Magnitude to the Power of 24:
[tex]\[ r^{24} = (\sqrt{2})^{24} = (2^{1/2})^{24} = 2^{12} = 4096 \][/tex]

2. Multiply the Argument by 24:
[tex]\[ n\theta = 24 \times \frac{\pi}{4} = 6\pi \][/tex]

### Step 3: Convert Back to Rectangular Form
We need to convert back to rectangular form, using:
[tex]\[ 4096 \left( \cos 6\pi + i \sin 6\pi \right) \][/tex]
We know that [tex]\( \cos 6\pi = 1 \)[/tex] and [tex]\( \sin 6\pi = 0 \)[/tex], since these functions are periodic with a period of [tex]\(2\pi\)[/tex].

So,
[tex]\[ \cos 6\pi = 1 \quad \text{and} \quad \sin 6\pi = 0 \][/tex]
Therefore,
[tex]\[ 4096 \left( \cos 6\pi + i \sin 6\pi \right) = 4096 (1 + i \cdot 0) = 4096 + 0i = 4096 \][/tex]

### Final Answer
The complex number [tex]\((1+i)^{24}\)[/tex] is:
[tex]\[ (1+i)^{24} = 4096 \][/tex]

To match the specific numerical output accurately, we can also provide the complex form:
[tex]\[ (4096.000000000006, -3.00969197358454e-12, \text{ which can be expressed as } 4096 - 3.00969197358454 \times 10^{-12}i ) \][/tex]

Slight numerical imprecisions arise due to computational errors but they are insignificantly small and can be considered as:
[tex]\[ (1+i)^{24} \approx 4096 \][/tex]