Mod Arg form (1 Viewer)

[zhiying]

So usually in Q2 in HSC they start you off with some complex number operations and then as you to convert something into mod arg form. I generally cbb writing out Pythagoras for mod and then drawing triangles for arg and just do it in my head.

If its worth a mark you think they'll allow it? And if its worth 2 marks you think they would require you to show all the working out?

 

[TheCardician]

Even I couldn't be bothered to write out the steps hahaha but I would do it in the exam anyway, best not to risk losing 1 mark.

 

[ohexploitable]

if it says "write down" then just do it in ya head br8

if it says "find" then work it out properly

ehhh

 

[D94]

You can look at the marking criteria to see where the marks are allocated. I used 2007 as a reference point - you would 1/2 if you got either the correct modulus OR argument, and you would get 2/2 for the correct solution, ie. the modulus AND argument. If you get the correct solution with out working out for this 2 mark question, I think you would be fine, but it doesn't have to apply to other cases though.

 

[apollo1]

just write the bloody thing down. it doesnt even take long lol.

 

[DVDVDVDV]

x + iy = (sqrt(x^2 + y^2))Cis(arctan(y/x))
Account for quadrant
You're done in 2 steps. Get over it, that's really good for a 2 mark question

 

[artosis]

seriously;

mod z = sqrt(x^2 + y^2)
arg z = arctan(y/x)

write in cis form
is that really that long?