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Find the value of ( 4+2i ) ( 4-2i ) given that { i }^{ 2 }=

Question

Find the value of $(4 + 2 i) (4 - 2 i)$ given that $i^{2} = - 1$ .

12

20

16 - 4 i

4 + 16 i

12 - 16 i

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Mateo Discussed

Find the value of

(4 + 2 i) (4 - 2 i)

given that

i^{2} = - 1

6 mins ago

Discuss this question LIVE

6 mins ago

Text solutionVerified

After expanding, we get

(4 + 2 i) (4 - 2 i) = 16 + 8 i - 8 i - 4 i^{4}

According to the question

i^{2} = - 1

\Rightarrow 16 - 4 i^{4}

\Rightarrow 16 - 4 (- 1)

\Rightarrow 16 + 4 = 20

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Question Text	Find the value of $(4 + 2 i) (4 - 2 i)$ given that $i^{2} = - 1$ .
Answer Type	Text solution:1
Upvotes	150