Complex Number Calculation: Real, Imaginary, and Absolute Value Explanation

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SUMMARY

The discussion focuses on calculating the real part, imaginary part, and absolute value of the complex expression i * [(1+2i)(5-3i)+3i/(1+i)]. The calculations yield (1+2i)(5-3i) = 11 + 7i, leading to (4 + 21i)/(1+i). The final result simplifies to (4i - 21)/(1+i). The key takeaway is that when a denominator contains an imaginary unit, multiplying by its conjugate simplifies the expression and clarifies the real and imaginary components.

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JaysFan31
Calculate the real part, the imaginary part, and the absolute value of the following expression:

i * [(1+2i)(5-3i)+3i/(1+i)].


So I did the math out this way:

(1+2i)(5-3i)= 11+7i
(11+7i)+3i/(1+i)= (4+21i)/(1+i)
i * [(4+21i)/(1+i)] = (4i-21)/(1+i)

Is this correct and what do you call the imaginary part and the real part if a denominator exists with an imaginary i?

Thanks for any help.
 
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Yeah I figured it out. You just multiply it by its conjugate earlier in the process.
 

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