Looking for trustworthy answers? Westonci.ca is the ultimate Q&A platform where experts share their knowledge on various topics. Connect with a community of experts ready to help you find solutions to your questions quickly and accurately. Our platform provides a seamless experience for finding reliable answers from a network of experienced professionals.

What is the value of the expression below?

[tex]\[ (-64)^{2 / 3} \][/tex]

A. -16
B. 4
C. 16
D. -4


Sagot :

To determine the value of [tex]\((-64)^{\frac{2}{3}}\)[/tex], we need to follow these steps:

1. Understand the properties of exponents and roots: The exponent [tex]\(\frac{2}{3}\)[/tex] means we should first take the cube root of [tex]\(-64\)[/tex] and then square the result. However, with a negative base and a rational exponent, we should expect a complex number.

2. Identify the cube root of [tex]\(-64\)[/tex]: The real cube root of [tex]\(-64\)[/tex] is [tex]\(-4\)[/tex] because [tex]\((-4)^3 = -64\)[/tex]. However, complex numbers will involve using complex cube roots as well.

3. Square the cube root: For a complex number [tex]\((-4)^{\frac{2}{3}}\)[/tex], squaring [tex]\(-4\)[/tex] involves complex analysis where:
- We can rewrite [tex]\(-64\)[/tex] in polar form: [tex]\(64e^{i\pi}\)[/tex].
- Using De Moivre's theorem and properties of exponents, [tex]\((-64)^{2/3} = (64e^{i\pi})^{2/3} = 64^{2/3} \cdot (e^{i\pi})^{2/3}\)[/tex].
- [tex]\(64^{2/3} = 16\)[/tex].
- [tex]\((e^{i\pi})^{2/3} = e^{2i\pi/3}\)[/tex], which corresponds to [tex]\(\pi/3\)[/tex] away from the initial position on the Argand plane, giving us the primary branch [tex]\(5\pi/3\)[/tex] and [tex]\(-\pi/3\)[/tex].
- Therefore, [tex]\(16 \cdot e^{2i\pi/3}\)[/tex] falls within:

Thus, the value of the expression [tex]\((-64)^{\frac{2}{3}}\)[/tex] in complex form turns out to be [tex]\((-7.999999999999996 + 13.856406460551018j)\)[/tex].

This does not directly align with any exact value from the given multiple-choice answers, so based on this complex form, there is no straightforward match to the provided options [tex]\(-16\)[/tex], [tex]\(4\)[/tex], [tex]\(16\)[/tex], or [tex]\(-4\)[/tex]. Perhaps the question might include a misunderstanding or they need to consider complex number solutions.
We appreciate your visit. Hopefully, the answers you found were beneficial. Don't hesitate to come back for more information. We hope this was helpful. Please come back whenever you need more information or answers to your queries. Get the answers you need at Westonci.ca. Stay informed with our latest expert advice.