Complex number question

[Stroodle]

Having trouble getting my head around this question:

The complex number is shown below.



The question asks to plot on the same diagram.

I'm fine with plotting and . I'm just not sure how to plot the addition of the two..

Cheers

[Yitzi_K]

Wouldn't it be just similar to addition of ordinates? Once you've plotted and , take the point and approximate the point you'd get if you added relative to O.

[Stroodle]

The answer says to use the triangle rule or parallelogram rule for addition, but I've never heard of these. Maybe it's cause my school uses the crappy Maths Quest text, or maybe it's not in the course anymore? It's from a 2003 exam.

[kamil9876]

It would be like adding vectors, so you would have to add x and y ordinates. Alternatively draw the parralelogram with side lengths your two vectors, the sum will therefore be the corner opposite to the origin.

[Stroodle]

Cheers. I get it. It's just adding two complex numbers, so you add the real and imaginary parts. Dunno what I was thinking..