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If Z= 2+2i, what is z^4?

User Prater
by
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2 Answers

3 votes

Final answer:

To find z^4, we can use the binomial theorem or direct multiplication. Using the binomial theorem, we simplify
(2 + 2i)^4 to find the result 64 + 16i.

Step-by-step explanation:

To find
z^4, we need to raise the complex number z = 2 + 2i to the power of 4. We can do this by using the binomial theorem or by direct multiplication.

Using the binomial theorem, we have:


(2 + 2i)^4 = C(4,0)(2)^4(2i)^0 + C(4,1)(2)^3(2i)^1 + C(4,2)(2)^2(2i)^2 + C(4,3)(2)^1(2i)^3 + C(4,4)(2)^0(2i)^4

After simplifying and performing the calculations, we get:


(2 + 2i)^4 = 16 + 32i + 32i^2 + 16i^3 + 16i^4

Simplifying further, we obtain:


(2 + 2i)^4 = 16 + 32i - 32 - 16i + 16


(2 + 2i)^4 = 64 + 16i

User Esben Von Buchwald
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4.8k points
5 votes

Answer:

D. 64 (cos(pi)+isin(pi))

Step-by-step explanation:

Put 2+2i into trigonometric form, raise the r value to the power of 4, and multiply the angle value (theta) by 4 to get the equation of z^4. In this case, r was 2(sqrt2), which raised to the 4th power was 64. The angle value was pi/4, which multiplied by 4 was pi. That's how we get the answer:

64 (cos(pi)+isin(pi)). How this helps!

User Joe Brunscheon
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4.4k points