Question 1103711
The complex number 3+4j, multiply by j, by j<sup>2</sup>, 
and by j<sup>3</sup>.
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We just need to know that j<sup>2</sup> = -1

We start with 3+4j,

(3+4j)
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multiply by j, 
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(3+4j)j = j(3+4j) = 3j+4j<sup>2</sup> = 3j+4(-1) = 3j-4 = -4+3j
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by j<sup>2</sup>,
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(-4+3j)j<sup>2</sup> = (-4+3j)(-1) = (-1)(-4+3j) = 4-3j
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and by j<sup>3</sup>.
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(4-3j)j<sup>3</sup> = (4-3j)(j<sup>2+1</sup>) = (4-3j)(j<sup>2</sup>j<sup>1</sup>) = (4-3j)(-1)(j) = (4-3j)(-j) =
(-j)(4-3j) = -4j+3j<sup>2</sup> = -4j+3(-1) = -4j-3 = -3-4j

Edwin</pre>