We read your photo as:

Convert the complex number z = sqrt(3) + i to polar form and calculate z5 using De Moivre's Theorem.

Mathematics

ScanSolve AI Answer

Step-by-step solution

5 steps
  1. Convert the complex number zz to polar form.

    Given z=3+iz = \sqrt{3} + i.
    The rectangular form is z=x+yiz = x + yi, where x=3x = \sqrt{3} and y=1y = 1.

    Calculate the modulus rr:

    r=∣z∣=x2+y2=(3)2+(1)2=3+1=4=2r = |z| = \sqrt{x^2 + y^2} = \sqrt{(\sqrt{3})^2 + (1)^2} = \sqrt{3 + 1} = \sqrt{4} = 2

    Calculate the argument θ\theta:
    Since x>0x > 0 and y>0y > 0, θ\theta is in the first quadrant.

    tan⁡θ=yx=13\tan \theta = \frac{y}{x} = \frac{1}{\sqrt{3}} θ=arctan⁡(13)=π6\theta = \arctan\left(\frac{1}{\sqrt{3}}\right) = \frac{\pi}{6}

    So, zz in polar form is z=2(cos⁡(π6)+isin⁡(π6))z = 2\left(\cos\left(\frac{\pi}{6}\right) + i \sin\left(\frac{\pi}{6}\right)\right).

  2. Use De Moivre's Theorem to evaluate z5z^5.

    De Moivre's Theorem states that for a complex number z=r(cos⁡θ+isin⁡θ)z = r(\cos \theta + i \sin \theta), its nn-th power is zn=rn(cos⁡(nθ)+isin⁡(nθ))z^n = r^n(\cos(n\theta) + i \sin(n\theta)).
    For n=5n=5:

    z5=25(cos⁡(5×π6)+isin⁡(5×π6))z^5 = 2^5\left(\cos\left(5 \times \frac{\pi}{6}\right) + i \sin\left(5 \times \frac{\pi}{6}\right)\right) z5=32(cos⁡(5π6)+isin⁡(5π6))z^5 = 32\left(\cos\left(\frac{5\pi}{6}\right) + i \sin\left(\frac{5\pi}{6}\right)\right)
  3. Evaluate the trigonometric functions for 5π6\frac{5\pi}{6}.

    The angle 5π6\frac{5\pi}{6} is in the second quadrant.

    cos⁡(5π6)=−cos⁡(π−5π6)=−cos⁡(π6)=−32\cos\left(\frac{5\pi}{6}\right) = -\cos\left(\pi - \frac{5\pi}{6}\right) = -\cos\left(\frac{\pi}{6}\right) = -\frac{\sqrt{3}}{2} sin⁡(5π6)=sin⁡(π−5π6)=sin⁡(π6)=12\sin\left(\frac{5\pi}{6}\right) = \sin\left(\pi - \frac{5\pi}{6}\right) = \sin\left(\frac{\pi}{6}\right) = \frac{1}{2}
  4. Substitute these values back into the expression for z5z^5.

    z5=32(−32+i12)z^5 = 32\left(-\frac{\sqrt{3}}{2} + i \frac{1}{2}\right) z5=32×(−32)+32×(12)iz^5 = 32 \times \left(-\frac{\sqrt{3}}{2}\right) + 32 \times \left(\frac{1}{2}\right)i z5=−163+16iz^5 = -16\sqrt{3} + 16i
  5. Compare the result with the given options.

    The calculated value for z5z^5 is −163+16i-16\sqrt{3} + 16i.
    The options provided in the image are:
    A. 2
    B. 3+i3+i
    C. 3−i3-i
    D. 4
    None of the given options match the calculated result.

    The final answer is −163+16i\boxed{-16\sqrt{3} + 16i}.

Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp