Consider the complex numberz=6(cos(165∘)+isin(165∘)). Which of the following complex numbers best approximates z ?Choose 1 answer:(A) −5.8−1.6i(B) −1.6+5.8i(C) −5.8+1.6i(D) −1.6−5.8i
Q. Consider the complex numberz=6(cos(165∘)+isin(165∘)). Which of the following complex numbers best approximates z ?Choose 1 answer:(A) −5.8−1.6i(B) −1.6+5.8i(C) −5.8+1.6i(D) −1.6−5.8i
Convert to rectangular form: Convert the given complex number in polar form to rectangular form using the cosine and sine values.The complex number z is given in polar form as z=6(cos(165°)+isin(165°)). To convert it to rectangular form, we use the definitions of cosine and sine for the given angle.
Calculate cosine and sine: Calculate the cosine and sine of 165°. Using the unit circle or trigonometric tables, we find that: cos(165°)≈−0.9659 (since 165° is in the second quadrant where cosine is negative) sin(165°)≈0.2588 (since 165° is in the second quadrant where sine is positive)
Multiply by modulus: Multiply the cosine and sine values by the modulus of the complex number.The modulus of z is 6. Therefore, we multiply the cosine and sine values by 6 to get the rectangular form:Real part: 6×cos(165°)≈6×(−0.9659)≈−5.7954Imaginary part: 6×sin(165°)≈6×0.2588≈1.5528
Round real and imaginary parts: Round the real and imaginary parts to one decimal place to match the answer choices.Real part rounded: −5.8Imaginary part rounded: 1.6
Form complex number: Form the complex number with the rounded real and imaginary parts.The approximate complex number in rectangular form is −5.8+1.6i.
Match with answer choices: Match the approximate complex number with the given answer choices.The approximate complex number −5.8+1.6i matches with choice (C) −5.8+1.6i.
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