Complex Number Arguments (1 Viewer)

[Web Addict]

Hi.

In the HSC exam, if a question asks me to write the answer is modulus-argument form and I write, say cis(3pi/2), instead of cis(-pi/2), would I lose marks?

Thank you.

 

[HSC2014]

I believe so, since the principal argument of z is defined for -pi < theta <= pi

 

[braintic]

I have been assured by HSC markers that the answer is NO you would not lose marks, it is perfectly correct.
The idea of the principal value of the argument is one of convenience only. I don't believe there has ever been an HSC question that asked for the principal value.

 

[HSC2014]

Oh, that's good to know